Xenotransplantation products and methods

ABSTRACT

A biological product for clinical xenotransplantation into a human and a method of preparing biological product for clinical xenotransplantation into a human involving producing a non-wild type, biologically engineered swine having a biologically engineered genome such that the swine does not express one or more extracellular surface glycan epitopes, is free of certain pathogens, is reared according to a bioburden-reducing procedure in a closed designated pathogen free herd, wherein the biological product is harvested following the swine being euthanized and the product is aseptically removed from the swine, the biological product is processed involving sterilization and storing the product in a sterile container, and the product does not contain one or more extracellular surface glycans, is free of certain designated pathogens, is biologically active and comprises live cells and tissues capable of vascularizing after xenotransplantation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. Ser. No. 17/017,002 filed Sep.10, 2020, which is a continuation of U.S. Ser. No. 16/593,785 filed Oct.4, 2019, which claims priority benefit of U.S. provisional applicationNo. 62/742,188, filed Oct. 5, 2018; 62/756,925, filed Nov. 7, 2018; U.S.62/756,955 filed Nov. 7, 2018; U.S. 62/756,977, filed Nov. 7, 2018; U.S.62/756,993, filed Nov. 7, 2018; U.S. 62/792,282, filed Jan. 14, 2019;U.S. 62/795,527, filed Jan. 22, 2019; U.S. 62/823,455, filed Mar. 25,2019; and U.S. 62/848,272, filed May 15, 2019, the disclosures of all ofwhich are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The subject matter disclosed herein relates to biological productsderived from genetically engineered organisms, and related methods, foruse in xenotransplantation.

BACKGROUND OF THE INVENTION

According to the United Network for Organ Sharing (“UNOS”), every tenminutes, someone is added to the national transplant waiting list, and20 people die each day waiting for a transplant. As of August 2019,there were about 114,000 people in need of a lifesaving organ transplantin the United States, with only about 10,000 donors identified and about36,000 transplants performed in 2018 (data from the United Network forOrgan Sharing (UNOS)). The need for specific organs in the United Statesis as follows (as of Aug. 12, 2019):

Organ Candidates Kidney 102,927 Liver 13,354 Pancreas 846Kidney/Pancreas 1,703 Heart 3,795 Lung 1,443 Heart/Lung 43 Intestine 231Total 124,363

More than 7,000 candidates died in 2016 while on the waiting list, orwithin 30 days of leaving the list for personal or medical reasons,without receiving an organ transplant. Sadly, each day, 30 people eitherdie or are removed from the waiting list (because they are too sick forthe requisite surgery) due to this inadequate supply of organs. Whilethe rate of divergence between available donors and unmet need ofrecipients has been improved marginally, this disparity has continued topresent day and remains considerable; the supply remains disastrouslyinadequate. For these patients, and the millions not included in thesestatistics who also would benefit significantly from tissue transplantssuch as cornea or pancreatic islet cells, “allotransplantation willnever prove to be a sufficient source.” Ekser B, Cooper D K C, Tector AJ (2015) The Need for Xenotransplantation as a Source of Organs andCells for Clinical Transplantation. International journal of surgery(London, England), 23(0 0): 199-204.

Beyond the shortage of organs, other significant issues related toallotransplantation exist and present a multifaceted problem, involvingsafety, logistical, ethical, legal, institutional, and culturalcomplications. Logistically, numerous factors must be considered priorto a successful organ donation and transplant procedure. Blood type andother medical factors must be evaluated for every donated organ, butfurther, each organ type presents unique characteristics that also mustbe weighed, such as post-mortem ischemia, immunological compatibility,patient location, and institutional capabilities. Allogeneic tissuesfrom human donors carry significant infectious disease risks. Dennerreports in 2018 that “[human] CMV is the single most importantinfectious agent affecting recipients of organ transplants, with atleast two-thirds of these patients having CMV infection aftertransplantation.” Denner J (2018) Reduction of the survival time of pigxenotransplants by porcine cytomegalovirus. Virology Journal, 15(1):171; Rubin R H (1990) Impact of cytomegalovirus infection on organtransplant recipients. Reviews of Infectious Diseases, 12 Suppl7:S754-766.

Regulations regarding tissue transplants include criteria for donorscreening and testing for adventitious agents, as well as strictregulations that govern the processing and distribution of tissuegrafts. The transmission of viruses has occurred as a result ofallotransplantation. Exogenous retroviruses (Human T-cell leukemia virustype 1 (HTLV-1), Human T-cell leukemia virus type 2 (HTLV-2), and Humanimmunodeficiency virus (HIV) have been transmitted by human tissuesduring organ and cell transplantation, as have viruses such as humancytomegalovirus, and even rabies. Due to technical and timingconstraints surrounding organ viability and post-mortem screening,absolute testing is hindered, and this risk cannot be eliminated.Immunological disparities between recipient and donor preventgraft-survival for extended durations, without immunosuppressiveregimens that pose their own set of complications and additional risks.When a patient receives an organ from a (non-self) donor (living ordeceased), the recipient's immune system will recognize the transplantas foreign. This recognition will cause their immune system to mobilizeand “reject” the organ unless concomitant medications that suppress theimmune system's natural processes are utilized. Benichou, et al.,describes the response to an allogeneic skin graft as a “potent” immuneresponse involving engagement of both the innate and adaptive immunesystems Abbas A K, Lichtman A H H, Pillai S (2017) Cellular andMolecular Immunology can blunt the natural immunological processes;unfortunately, these medications are often a lifelong requirement afterorgan transplantation and increase recipient susceptibility to otherwiseroutine pathogens. While these drugs allow transplant recipients totolerate the presence of foreign organs, they also increase the risk ofinfectious disease and symptoms associated with a compromised immunesystem, as a “broad array of organisms may be transmitted with humanallografts.” Fishman J A, Greenwald M A, Grossi P A (2012) Transmissionof infection With Human Allografts: Essential Considerations in DonorScreening. Clinical Infectious Diseases, 55(5):720-727.

One, often overlooked logistical constraint involves the intricate andtimely preservation methods of donated organs necessary to maintainviability between the time of procurement and transplantation. This is acritical logistical and scientific underpinning of transplantation as afield of medicine and as a promising, clinical adjunct therapy.Limitations on organ preservation are considerable and directly impactsurgical capacity. Examples of common, maximum organ preservation timesinclude: kidney, 24-36 hours; pancreas, 12-18 hours; liver, 8-12 hours;heart or lung, 4-6 hours. The fundamental reason for these restrictive,limiting timeframes is due to the inability to preserve the fundamentalvital capacity of the numerous and diverse cells comprising the largertissue or organ. Interruption or complete termination of necessary andhighly complex, interdependent cellular activity thereby erodes thepotential clinical utility of the transplant.

Despite these drawbacks, organ transplantation is unquestionably thepreferred therapy for most patients with end stage organ failure, inlarge part due to a lack of viable alternatives. However, the advent oforgan transplantation as a successful life-saving therapeuticintervention, juxtaposed against the paucity of organs available totransplant, unfortunately places medical professionals in anideologically vexing position of having to decide who lives and whodies. Ultimately, alternative and adjunct treatment options that wouldminimize the severe shortcomings of allotransplant materials whileproviding the same mechanism of action that makes them so effectivewould be of enormous benefit to patients worldwide.

With regard to the organ of skin, patients with severe and extensive,deep partial and full thickness burn wounds are in immediate need oftemporary treatment options to bridge them prior to more permanenttreatments. During this critical period, patients with severe burns areat risk of deteriorating clinical condition due to infection fromopportunistic pathogens, disrupted skin barrier, and impairment ofimmune response, as well as hypovolemia through fluid loss at the burnsite. This is frequently followed by electrolyte, temperature and pHimbalances that contribute to organ failure, and possibly death. Whileit would be ideal to utilize autograft to treat such injuries, thesupply of the patient's own skin is often limited during the acute phaseof burn care (within 96 hours of injury) especially in cases where burnscover 20% or more of total body surface area. More importantly,autologous graft harvest is often clinically contraindicated as itresults in further insult to the patient's already compromisedhomeostasis and worsens morbidity. See, e.g., Johnson,“Partial-thickness burns: identification and management,” Adv Skin.Wound Care. 2003; 16(4):178-87. Thus, in instances where autograft isnot available and/or contraindicated, the current method is to utilizehuman cadaveric allograft (“HCA”) to provide temporary wound coverageuntil autograft is available and/or indicated. Unfortunately, given theinherent logistical and supply constraints, as well as infectious agentconcerns, the availability of HCA is severely limited.

To address the unmet clinical need due to limited availability ofautograft and allograft solutions, other “stop-gap” temporary coveragematerials are commonly used. These include various synthetic or othertissue-based products comprised of terminally sterilized, non-viablecells used primarily to attempt to treat superficial burns and provide abarrier for infection. Examples of such products include Biobrane®,Transcyte®, cultured epidermal allogeneic keratinocytes, Dermagraft,Apligraf®, and hydrocolloid dressings such as Aquacel®. Other woundclosure products include non-genetically altered porcine xenografts(Gal+), and tissue-engineered delivery systems. Many of these woundcover and closure products have limited indications and otherlimitations as described in the literature. See, e.g., Thornton J F andGosman A A, “Skin Grafts and Skin Substitutes and Principles of Flaps,”Baylor University Medical Center, 2004 10(1): 2-78. Such products do notvascularize and are not intended for treatment of severe and extensive,deep partial and full thickness burn wounds and allow forvascularization of the wound bed. Prior to the present invention, noskin substitute is able to approximate the biologic properties of viablehuman skin and there is no satisfactory replacement for human allograftskin. Thus, with regard to skin in particular, there remains a need fora high quality, temporary method of coverage for severe and extensive,deep partial and full thickness burn wounds to provide a barrierfunction (equivalent to or better than allograft) and vascularize in thewound bed.

The urgent need for organs and other transplantation tissue generally,including for temporary therapies while more permanent organs or othertissue are located and utilized, has led to investigation intoutilization of organs, cells and tissue from non-human sources,including other animals for temporary and/or permanentxenotransplantation.

Pigs have long been considered a potential non-human source of organs,tissue and/or cells for use in human xenotransplantation given thattheir size and physiology are compatible with humans.Xenotransplantation from swine to humans, however, has significantroadblocks, not the least of which is hyperacute rejection where naturalhuman antibodies target epitopes on the animal cells, causing rejectionand failure of the transplanted organs, cells or tissue. Otherroadblocks include delayed xenograft rejection, acute cellularrejection, chronic rejection, risks of cross-species transmission ofdisease or parasites.

One cause of hyperacute rejection results from the expression ofalpha-1,3-galactosyltransferase (“alpha-1,3-GT”) in porcine cells, whichcauses the synthesis of alpha-1,3-galactose epitopes. Except for humans,apes and Old World monkeys, most mammals carry glycoproteins on theircell surfaces that contain galactose alpha 1,3-galactose (see, e.g.,Galili et al., “Man, apes, and old world monkeys differ from othermammals in the expression of α-galactosyl epitopes on nucleated cells,”J. Biol. Chem. 263: 17755-17762 (1988). Humans, apes and Old Worldmonkeys have a naturally occurring anti-alpha gal antibody that isproduced and binds to glycoproteins and glycolipids having galactosealpha-1,3 galactose (see, e.g., Cooper et al., “Genetically engineeredpigs,” Lancet 342:682-683 (1993). Accordingly, when natural type swineproducts are utilized in xenotransplantation, human antibodies will beinvoked to confront the foreign alpha-1,3-galactose epitopes, andhyperacute rejection normally follows.

A variety of methods have been attempted to modify swine to eliminateexpression of alpha-1,3-galactosyltransferase, which has been shown todecrease hyperacute rejection as compared to wild-type swine. Forexample, “knockout” and “knock-in” swine are disclosed in U.S. Pat. No.7,795,493 (“Phelps”), U.S. Pat. No. 7,547,816 (“Day”), and, U.S. Pat.No. 547,522 (“Hawley”). Each of those references is incorporated hereinby reference in its entirety.

Other genetic modifications to swine besides eliminating expression ofalpha-1,3-galactosytransferase can also serve to decrease immunologicalrejection of transplanted swine cells, tissues, and/or organs, by ahuman recipient. For example, eliminating expression of Neu5Gc isanother approach to reduce immunological rejection. See, e.g., Scobie,L., “Long-Term IgG Response to Porcine Neu5Gc Antigens withoutTransmission of PERV in Burn Patients Treated with Porcine SkinXenografts,” The Journal of Immunology, 191: 2907-2915 (2013)(“Scobie”), the entire disclosure of which is incorporated herein byreference. All mammals express Neu5Ac, a sialic acid. All animals excepthumans convert Neu5Ac to Neu5Gc using Neu5Ac hydroxylase, which isencoded by the CMAH gene. Thus, similar to thealpha-1,3-galactosyltransferase epitope, Neu5Gc is expressed on swinecells, but is recognized as foreign by human recipients ofxenotransplant products, leading to eventual rejection. Thus,eliminating CMAH, the enzyme responsible for the Neu5Ac to Neu5Gcconversion, could further engineer the cells of organs derived fromswine for xenotransplantation and reduce risk of rejection in humanrecipients.

In addition to alpha-1,3-galactosytransferase and Neu5Gc, eliminatingexpression of β1,4-N-acetylgalactosaminyltransferase (B4GALNT2) isanother approach to reduce immunological rejection. B4GALNT2 maycontribute to the antibody response observed in swine to humantransplants, and in the swine to baboon model indicate that it producesa glycan that elicits an immune response from the recipient. See, e.g.,Byrne, G., “Cloning and expression of porcineβ1,4-N-acetylgalactosaminyl transferase encoding q new xenoreactiveantigen,” Xenotransplantation, 21: 543-554 (2014) (“Byrne”), the entiredisclosure of which is incorporated herein by reference. Disrupting theB4GALNT2 gene may reduce the immune response to swine cells,particularly when those cells have also hadalpha-1,3-galactosytransferase and CMAH removed. See, e.g., Byrne.Aspects of the combined removal of alpha-1,3-galactosyltransferase,Neu5Gc, and β1,4-N-acetylgalactosaminyltransferase, also referred to as“triple knockout,” are described in U.S. Patent Publication No.US2017/0311579, the entire disclosure of which is incorporated herein byreference. In many cases, the prior art methods involved attempts toaddress the resultant negative effects of the xenotransplantation, e.g.,via administration of immunosuppressants. While the previously usedmethods require immunosuppressive drugs, use of immunosuppressants oftenlead to life-threatening malignancies and infections. In other cases,the prior art methods resolved to knockout animal genes and/or to inserthuman genes to create transgenic animals, but doing so resulted inanimals that were unable to survive and thrive due to compromised immunesystems and other phenotypic complications. In such cases, disruption ofswine glycan and/or SLA genes made the cells vulnerable to lysis bynatural killer cells. Natural killer cells are quick, versatilelymphocytes that function in innate immunity, adaptive immunity, andreproduction. Each human has a large diversity of natural killer cells.Prior xenotransplantation studies have reported problems includingnatural killer cell-mediated lysis after transplantation, as well asdifficulties maintaining antiviral immunity, and autoimmune disorders inthe donor animals.

Despite such publications, complex issues concerning xenotransplantationproducts in humans remain unsolved and guidance for providing viablexenotransplantation products remains vague, contradictory, and genericwhere specificity is required for safety and efficacy. There is noxenotransplantation product comprising live animal cells, tissues, ororgans approved for marketing and very few clinical trials. The industryhas faced safety concerns, e.g., potential transmission of pathogens,coupled with the lack of meaningful regulatory guidance on approvedmanufacturing procedures and product characteristics. While variouspublications have reported advances, e.g., in academic settings, nonehas resulted in an approved xenotransplantation product comprising liveanimal cells, tissues, or organs, and good manufacturing practice (GMP)regulations have not been promulgated for such products or manufacturingprocesses. The present invention therefore addresses long-felt but unmetneed for translating the science of xenotransplantation into a clinicalreality.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention a method is provided forproducing a biological product for xenotransplantation into a humanrecipient, said biological product comprising live cells and tissuesthat vascularize after xenotransplantation, the method including:producing a non-wild type, biologically engineered swine, wherein saidswine has a biologically engineered genome such that it does not expressone or more extracellular surface glycan epitopes; confirming that saidswine is free of at least the following zoonotic pathogens:

-   -   (i) Ascaris species, cryptosporidium species, Echinococcus,        Strongyloids sterocolis, and Toxoplasma gondii in fecal matter;    -   (ii) Leptospira species, Mycoplasma hyopneumoniae, porcine        reproductive and respiratory syndrome virus (PRRSV),        pseudorabies, transmissible gastroenteritis virus (TGE)/Procine        Respiratory Coronavirus, Toxoplasma Gondii in antibody titers;    -   (iii) Porcine Influenza;    -   (iv) the following bacterial pathogens as determined by        bacterial culture: Bordetella bronchisceptica,        Coagulase-positive staphylococci, Coagulase-negative        staphylococci, Livestock-associated methicillin resistant        Staphylococcus aureus (LA MRSA), Microphyton and Trichophyton        spp.;    -   (v) Porcine cytomegalovirus; and    -   (vi) Brucella suis;        maintaining the swine according to a bioburden-reducing        procedure, said procedure comprising maintaining the swine in an        isolated closed herd, wherein all other animals in the isolated        closed herd are confirmed to be free of said zoonotic pathogens,        wherein the swine is isolated from contact with any non-human        animals and animal housing facilities outside of the isolated        closed herd; harvesting a biological product from said swine,        wherein said harvesting comprises euthanizing the swine and        aseptically removing the biological product from the swine;        processing said biological product comprising sterilization        after harvesting using a sterilization process that does not        reduce cell viability to less than 50% cell viability in a        3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide        (MTT)-reduction assay and does not reduce mitochondrial activity        to less than 50% mitochondrial activity; and storing said        biological product in a sterile container.

In accordance with one aspect of the invention, a method is provided forproducing a biological product suitable for xenotransplantation into ahuman recipient, the method including: producing a non-wild type,biologically engineered swine, wherein said swine is produced throughnatural breeding and natural birthing, wherein said swine has abiologically engineered genome such that it does not express one or moreextracellular surface glycan epitopes, and wherein said swine is free ofat least the following pathogens: Ascaris species, cryptosporidiumspecies, Echnococcus, Strongyloids sterocolis, Toxoplasma gondii,Brucella suis, Leptospira species, mycoplasma hyopneumoniae,pseudorabies, Toxoplasma Gondii, staphylococcus species, Microphytonspecies, and Trichophyton species, porcine influenza, cytomegalovirus,arterivirus, and coronavirus; rearing the swine and maintaining theswine according to a bioburden-reducing procedure, said procedurecomprising maintaining the swine in a closed herd, wherein all otheranimals in the closed herd are confirmed to be free of at least thefollowing pathogens: Ascaris species, cryptosporidium species,Echnococcus, Strongyloids sterocolis, Toxoplasma gondii, Brucella suis,Leptospira species, mycoplasma hyopneumoniae, pseudorabies, ToxoplasmaGondii, staphylococcus species, Microphyton species, and Trichophytonspecies, porcine influenza, cytomegalovirus, arterivirus, andcoronavirus, wherein the swine is isolated from contact with anynon-human animals and animal housing facilities outside of the closedherd; harvesting a biological product from said swine, wherein saidharvesting comprises euthanizing the swine and aseptically removing thebiological product from the swine; processing said biological productcomprising sterilization within 15 hours of harvesting and storing saidbiological product in a sterile container, wherein said biologicalproduct does not contain one or more extracellular surface glycans,wherein said product is free of Ascaris species, cryptosporidiumspecies, Echnococcus, Strongyloids sterocolis, Toxoplasma gondii,Brucella suis, Leptospira species, mycoplasma hyopneumoniae,pseudorabies, Toxoplasma Gondii, staphylococcus species, Microphytonspecies, and Trichophyton species, porcine influenza, cytomegalovirus,arterivirus, and coronavirus, and wherein said product is biologicallyactive and comprises live cells and tissues capable of vascularizingafter xenotransplantation, wherein cellular mitochondrial activity ofsaid product is greater than 50% as measured by MTT assay; wherein saidproduct is less immunogenic when transplanted into a humanxenotransplant recipient as compared to a biological product obtained axenotransplantation product made from conventional Gal-T knockout swine,from conventional triple knockout swine, from transgenic swine, fromwild-type animals, and/or allograft, wherein said product is lessantigenic when transplanted into a human xenotransplant recipient ascompared to a biological product obtained from a xenotransplantationproduct made from conventional Gal-T knockout swine, from conventionaltriple knockout swine, from transgenic swine, from wild-type animals,and/or allograft, and wherein said product is resistant to rejection bythe human xenotransplant recipient in the absence of administration ofimmunosuppressant drugs or other immunosuppressant therapies to thehuman xenotransplant recipient.

In a further aspect of the invention, following the clinicalxenotransplantation of the product into a human recipient, the productexhibits a clinical benefit that is on par or enhanced above anallograft product. In a further aspect of the invention, the productcomprises an organ or tissue, for example, including a liver, a kidney,lung, skin or nerve. In a further aspect of the invention, the productis compatible with vascularization in the region of the transplant inthe patient following the xenotransplantation. In a further aspect ofthe invention, with regard to skin, the product is compatible with theproduction of collagen in the region of the transplant in the patientfollowing the xenotransplantation. In some aspects, clinical benefitsmay include decreased graft dislocation, increased graft adherence,granulation at level with surrounding tissue; less than 20%, 10%, 5% or2% hyper-granulation, hematoma less than 20%, 10%, 5% or 2% of woundsize; and fibrin deposition of less than 20%, 10%, 5% or 2% of woundsize, reduced bacterial infection compared to allograft, e.g., colonycounts of less than 10⁵ g/tissue, reduced cellulitis, reduced erythema,reduced edema, reduced hyperesthesia, reduced induration, reducedtenderness, reduced itching, reduced abscesses, reduced incidence oftoxic shock syndrome, reduced colonization of toxin-1 producing S.aureus, reduced incidence of sepsis and septic shock, reducedcolonization by E. coli, P. aeruginosa, Klebsiella spp., Providenciaspp., enterobacteriaceae, and yeasts such as C. albicans. In a furtheraspect, the product may form an occlusive fibrin seal. In a furtheraspect, the product may incorporate into the transplantation site orhealing site. In a further aspect, the product may reduce or preventinfection at the transplantation site or the healing site, increase orretain fluids at the transplantation site or the healing site, increaseor retain electrolytes at the transplantation site or the healing site,increase or retain temperature homeostasis at the transplantation siteor the healing site, reduce scarring at the transplantation site or thehealing site, reduce or eliminate sepsis, reduce or eliminate proteinlosses, provide, improve or facilitate restoration of normal bodilyfunctions, or a combination thereof. In a further aspect of theinvention, the product is capable of being transplanted in the absenceof immunosuppressant drugs or other immunosuppressant therapies. In someaspects, immunosuppressants are not used according to the presentdisclosure prior to, during, and/or after transplantation of thexenotransplantation product of the present disclosure. In some aspects,immunosuppressants may be used according to the present disclosure priorto, during, and/or after transplantation of the xenotransplantationproduct of the present disclosure. In some aspects, immunosuppressantsare used according to the present disclosure after transplantation ofthe xenotransplantation product of the present disclosure to prolong theadherence of an already transplanted xenotransplantation product.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method of preparing biological product forclinical xenotransplantation into a human comprising selecting a knownhuman major histocompatibility complex gene sequence or sequencing ahuman recipient's major histocompatibility complex gene, geneticallymodifying cells of a swine to replace a portion of the swine's majorhistocompatibility complex gene sequence with a corresponding portion ofthe known human major histocompatibility complex gene sequence or acorresponding portion of the human recipient's major histocompatibilitycomplex gene sequence such that the swine's cells express thecorresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence, isolatingone or more cells, tissues, and/or organs from the swine that expressthe corresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence, wherein theisolated cells, tissues, and/or organs are the biological product.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method of preparing a geneticallyreprogrammed swine comprising a nuclear genome having disruptedalpha-1,3 galactosyltransferase gene, and genetically modified such thatit expresses a major histocompatibility complex of a known humansequence or a human recipient of a cell, a tissue, and/or an organisolated from said genetically reprogrammed swine, the method comprisingselecting a known human major histocompatibility complex sequence orsequencing the human recipient's major histocompatibility complex gene,obtaining a swine comprising a nuclear genome having at least onedisrupted swine surface glycan gene, genetically modifying cells of theswine to replace portions of the swine's major histocompatibilitycomplex gene with corresponding portions of the known human majorhistocompatibility complex gene or corresponding portions of the humanrecipient's major histocompatibility complex gene such that the swine'scells express portions of the human recipient's major histocompatibilitycomplex.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method of delaying, reducing, orpreventing rejection, separation, or adverse reactions toxenotransplanted tissues in a human recipient, comprising selecting aknown human major histocompatibility complex gene sequence or sequencingthe human recipient's major histocompatibility complex gene, obtaining aswine comprising a nuclear genome having disrupted alpha-1,3galactosyltransferase gene, genetically modifying cells of the swine toreplace a portion of the swine's major histocompatibility complex genewith a corresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence such that theswine's cells express the corresponding portion of the known human majorhistocompatibility complex gene sequence or the corresponding portion ofthe human recipient's major histocompatibility complex gene sequence,isolating cells, tissue, and/or an organ from the geneticallyreprogrammed swine that express the corresponding portion of the knownhuman major histocompatibility complex gene sequence or thecorresponding portion of the human recipient's major histocompatibilitycomplex gene sequence, and transplanting the isolated cells, tissue,and/or an organ from the genetically reprogrammed swine into the humanrecipient.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a biological product for clinicalxenotransplantation derived from a non-wild type, biologicallyengineered, non-human organism, wherein said organism from which saidbiological product is derived is produced through natural breedingand/or assisted reproductive technologies, and wherein said organism hasa biologically engineered genome such that it does not express one ormore extracellular surface glycan epitopes, and wherein said organism isfree of at least the following pathogens: Ascaris species,cryptosporidium species, Echnococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, pseudorabies, Toxoplasma Gondii, staphylococcus species,Microphyton species, and Trichophyton species, porcine influenza,cytomegalovirus, arterivirus, and coronavirus, wherein said organism isnot transgenic, wherein said product does not contain one or moreextracellular surface glycans, wherein said product is free of: Ascarisspecies, cryptosporidium species, Echnococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, pseudorabies, Toxoplasma Gondii, staphylococcus species,Microphyton species, and Trichophyton species, porcine influenza,cytomegalovirus, arterivirus, and coronavirus, wherein said product hasnot been terminally sterilized, wherein said product is less immunogeniccompared to biological product obtained from a xenotransplantationproduct made from conventional Gal-T knockout swine, from conventionaltriple knockout swine, from transgenic swine, from wild-type animals,and/or allograft, wherein said product is less antigenic whentransplanted into a human xenotransplant recipient as compared to abiological product obtained from a xenotransplantation product made fromconventional Gal-T knockout swine, from conventional triple knockoutswine, from transgenic swine, from wild-type animals, and/or allograft,and wherein said product is biologically active and comprises live cellsand tissues capable of vascularizing after xenotransplantation.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method for the production of asecond-generation non-wild type, biologically engineered piglet, themethod including: delivering a non-wild type, biologically engineeredpiglet from a pregnant sow through Cesarean section, wherein said sowwas produced through natural breeding and/or assisted reproductivetechnologies, and holding said delivered piglet in an isolated closedherd wherein all other pigs in the isolated closed herd are confirmed tobe free of at least the following pathogens: cytomegalovirus,arterivirus, and coronavirus, and wherein said piglet is free of atleast the following pathogens: cytomegalovirus, arterivirus, andcoronavirus; rearing said piglet in said isolated closed herd; matingsaid piglet, upon sexual maturity, with another pig that is alsomaintained in said isolated closed herd and free of said pathogens; anddelivering a new piglet resulting from said mating, wherein said newpiglet is the second-generation non-wild type, biologically engineeredpiglet that is also free of said pathogens.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method of treating a human subject who hassuffered an injury requiring an organ, nerve, cell, or tissuetransplant, the method including transplanting an organ, nerve, cell, ortissue from a second-generation non-wild type, biologically engineeredpiglet to the subject, wherein the second-generation non-wild type,biologically engineered piglet is produced by the method of the presentdisclosure and wherein immunosuppressant drugs or otherimmunosuppressant therapies are not administered to the subject.

In accordance with another exemplary aspect of the invention, thepresent disclosure provides a method for the production of a piglet isprovided, comprising: delivering a piglet from a pregnant sow throughCesarean section, wherein the sow was produced through natural breedingand/or assisted reproductive technologies, and holding the deliveredpiglet in an environment maintained to be designated pathogen free,wherein the piglet is free of at least the following pathogens:cytomegalovirus, arterivirus, and coronavirus; rearing the piglet in theenvironment; mating the piglet, upon sexual maturity, with another pigthat is also maintained in the environment and free of the pathogens;and delivering a new piglet resulting from the mating, wherein the newpiglet is also free of the pathogens. In a further aspect of theinvention, a pig is produced by such a method. Further aspects of themethod include harvesting a biological product from the new piglet,wherein the product comprises an organ or tissue, the organ comprises aliver, kidney, or skin, and/or the tissue comprises a nerve.

In accordance with another exemplary aspect of the invention, method forthe xenotransplantation of a product into a human patient is provided,which comprises obtaining a product derived from a non-wild type,genetically engineered, non-human organism having a genome with adisrupted alpha-1,3 galactosyltransferase gene, wherein the organism ismaintained in a designated pathogen free environment and is free of atleast the following pathogens: cytomegalovirus, arterivirus, andcoronavirus, and wherein the product is biologically active; andtransplanting the product into a human recipient, wherein upon thetransplantation, the product exhibits a clinical benefit. Furtheraspects of the method include the product comprising an organ or tissue,the organ comprising a liver, kidney or skin, the tissue comprising anerve, the transplantation occurring in the absence of immunosuppressantdrugs or other immunosuppressant therapies, the product being compatiblewith vascularization in the region of the transplant in the patientfollowing the xenotransplantation, the product, e.g., skin beingcompatible with the production of collagen in the region of thetransplant in the patient following the xenotransplantation, theclinical benefit being enhanced above an allograft product, the organismfrom which the biological product is derived being produced throughnatural breeding and/or assisted reproductive technologies. In someaspects, the method for the xenotransplantation of a product into ahuman patient may further include archiving human recipient samples,such as blood and tissue samples, to allow future monitoring forpotential infections, following recipients for their lifetimes to detectany unusual symptoms, and/or archiving samples of thexenotransplantation product. Any non-human animal cells used for aco-culture process should also be archived.

Yet other genetic modifications to swine can also serve to decreaseimmunological rejection of transplanted swine cells, tissues, and/ororgans, by a human recipient. For example, the major histocompatibilitycomplex (MHC) (including subgroups Class I, Class II and Class III)comprises a set of cell surface proteins essential for the acquiredimmune system to recognize foreign molecules in vertebrates, and MHCmolecules bind to antigens derived from pathogens and display them onthe cell surface for recognition by the appropriate T-cells. See FIG.25.

Major histocompatibility complex class I (MHCI) and class II (MHCII)molecules display peptides on antigen-presenting cell surfaces forsubsequent T-cell recognition. See FIG. 22. Within the human population,allelic variation among the classical MHCI and II gene products is thebasis for differential peptide binding, thymic repertoire bias andallograft rejection. MHC molecules are cell-surface glycoproteins thatare central to the process of adaptive immunity, functioning to captureand display peptides on the surface of antigen-presenting cells (APCs).MHC class I (MHCI) molecules are expressed on most cells, bindendogenously derived peptides with sizes ranging from eight to ten aminoacid residues and are recognized by CD8 cytotoxic T-lymphocytes (CTL).See FIG. 18 and FIG. 27. On the other hand, MHC class II (MHCII) arepresent only on specialized APCs, bind exogenously derived peptides withsizes varying from 9 to 22 residues, and are recognized by CD4 helperT-cells. See FIG. 28. These differences indicate that MHCI and MHCIImolecules engage two distinct arms of the T-cell-mediated immuneresponse, the former targeting invasive pathogens such as viruses fordestruction by CD8 CTLs, and the latter inducing cytokine-basedinflammatory mediators to stimulate CD4 helper T-cell activitiesincluding B-cell activation, maturation and antibody production. In someaspects, the biological product of the present disclosure is notrecognized by CD8+ T cells, do not bind anti-HLA antibodies, and areresistant to NK-mediated lysis.

In the human, MHC molecules are referred to as HLA, an acronym for humanleukocyte antigens, and are encoded by the chromosome 6p21.3-located HLAregion.8,9 The HLA segment is divided into three regions (fromcentromere to telomere), class II, class III and class I. See FIG. 19.Classical class I and class II HLA genes are contained in the class Iand class II regions, respectively, whereas the class III locus bearsgenes encoding proteins involved in the immune system but notstructurally related to MHC molecules. The classical HLA class Imolecules are of three types, HLA-A, HLA-B and HLA-C. Only the a chainsof these mature HLA class I molecules are encoded within the class I HLAlocus by the respective HLA-A, HLA-B and HLA-C genes. See FIG. 13. Incontrast, the beta-2 microglobulin β2m chain encoded by the β2m gene islocated on chromosome 15. The classical HLA class II molecules are alsoof three types (HLA-DP, HLA-DQ and HLA-DR), with both the a and (3chains of each encoded by a pair of adjacent loci. In addition to theseclassical HLA class I and HLA class II genes, the human MHC locusincludes a long array of HLA pseudogenes as well as genes encodingnon-classical MHCI and MHCII molecules. HLA-pseudogenes are anindication that gene duplication is the main driving force for HLAevolution, whereas non-classical MHCI and MHCII molecules often serve arestricted function within the immune system quite distinct from that ofantigen presentation to αβ TCRs.

In transplantation, MHC molecules act themselves as antigens, provokingan immune response from a recipient, leading to transplant rejection.Accordingly, eliminating the expression of specific MHC molecules fromthe donor animals will serve to reduce immunological rejection oftransplanted swine cells, tissues, and/or organs, into a humanrecipient. Human MHC class I and II are also called human leukocyteantigen (HLA). The present inventors have found that in order for thedonor animals to survive and thrive, it is necessary to retain certainMHC molecules (e.g., SLAs) that provide the donor animals with aminimally competent immune system. Prior art strategies that rely ondeletion of the MHC gene pose significant risks to the donor animals,e.g., severe combined immune deficiency (SCID). Prior art strategiesthat do not reprogram the swine genome pose significant risks ofrejection to the human recipient, or require significant and endless useof antisuppressants. The biological products of the present disclosureavoid many human immune pathways including antigen presentation andgeneration of adaptive immunity, natural killer cell-mediated lysis, Tcell-mediated lysis, and/or macrophage phagocytosis. Accordingly, thebiological product of the present disclosure provides long-term survivalof xenotransplanted products in human recipients without the need forsystemic immunosuppression.

The human leukocyte antigen (HLA) system or complex is a gene complexencoding the major histocompatibility complex (MHC) proteins in humans.These cell-surface proteins are responsible for the regulation of theimmune system in humans. The HLA gene complex resides on a 3 Mbp stretchwithin chromosome 6p21. See FIG. 14. HLA genes are highly polymorphic,which means that they have many different alleles, allowing them tofine-tune the adaptive immune system. See FIG. 15. The proteins encodedby certain genes are also known as antigens, as a result of theirhistoric discovery as factors in organ transplants. Different classeshave different functions. See FIG. 16 and FIG. 17.

HLAs corresponding to MHC class I (A, B, and C) which all are the HLAClass I group present peptides from inside the cell. For example, if thecell is infected by a virus, the HLA system brings fragments of thevirus to the surface of the cell so that the cell can be destroyed bythe immune system. These peptides are produced from digested proteinsthat are broken down in the proteasomes. In general, these particularpeptides are small polymers, about 9 amino acids in length. Foreignantigens presented by MHC class I attract killer T-cells (also calledCD8 positive- or cytotoxic T-cells) that destroy cells. MHC class Iproteins associate with β2-microglobulin, which unlike the HLA proteinsis encoded by a gene on chromosome 15.

HLAs corresponding to MHC class II (DP, DM, DO, DQ, and DR) presentantigens from outside of the cell to T-lymphocytes. These particularantigens stimulate the multiplication of T-helper cells (also called CD4positive T cells), which in turn stimulate antibody-producing B-cells toproduce antibodies to that specific antigen. Self-antigens aresuppressed by regulatory T cells. The affected genes are known to encode4 distinct regulatory factors controlling transcription of MHC class IIgenes. These transacting factors are the class II transactivator and 3subunits of regulatory factor X (RFX): RFX containing ankyrin repeats(RFXANK), the fifth member of the RFX family (RFX5), and RFX-associatedprotein (RFXAP). Mutations in one of each define 4 distinctcomplementation groups termed A, B, C, and D, respectively.

HLAs corresponding to MHC class III encode components of the complementsystem. HLAs have other roles. They are important in disease defense.They are the major cause of organ transplant rejections. They mayprotect against or fail to protect (if down-regulated by an infection)against cancers. Mutations in HLA may be linked to autoimmune disease(examples: type I diabetes, coeliac disease). HLA may also be related topeople's perception of the odor of other people, and may be involved inmate selection, as at least one study found a lower-than-expected rateof HLA similarity between spouses in an isolated community.

Aside from the genes encoding the 6 major antigen-presenting proteins,there are a large number of other genes, many involved in immunefunction, located on the HLA complex. Diversity of HLAs in the humanpopulation is one aspect of disease defense, and, as a result, thechance of two unrelated individuals with identical HLA molecules on allloci is extremely low. HLA genes have historically been identified as aresult of the ability to successfully transplant organs betweenHLA-similar individuals.

Each human cell expresses six MHC class I alleles (one HLA-A, -B, and -Callele from each parent) and six to eight MHC class II alleles (oneHLA-DP and -DQ, and one or two HLA-DR from each parent, and combinationsof these). The MHC variation in the human population is high, at least350 alleles for HLA-A genes, 620 alleles for HLA-B, 400 alleles for DR,and 90 alleles for DQ. In humans, MHC class II molecules are encoded bythree different loci, HLA-DR, -DQ, and -DP, which display ˜70%similarity to each other. Polymorphism is a notable feature of MHC classII genes. The present disclosure includes identifying the nucleotidesequence to be reprogrammed into the donor animal, finding andselectively replacing corresponding sections of SLA with the nucleotidesequence to be reprogrammed, e.g., 50-80 nucleotides, 60-72 nucleotides,62-68 nucleotides. In some aspects, MHC class II genes are reprogrammed.Maps of SLA genes are available. See FIGS. 25 and 26. Thus, the presentdisclosure includes reprogramming small sections of genetic code ratherthan making a transgenic animal having human genes inserted into theanimal's genome. Advantages of the present disclosure over prior artMHC-silencing techniques include providing a biologically reprogrammedswine that has a well-functioning immune system, is substantially freeof a specific group of pathogens that have been identified by theinventors to be critical to exclude in order to achieve the advantagesof the disclosed invention, and provides xenotransplantation productsthat are “invisible” to the human recipient's immune system, i.e.significantly delay or avoid rejection by the human recipient's immunesystem.

Any two individuals who are not identical twins will express differingMHC molecules. While MHC-knockout cells have been made, such cellssuffer from issues including compromise of activation of downstreamadaptive immune responses due to the deletion of MHC alleles. Byreplacing MHC alleles of the swine, the present disclosure providesimproved donor-recipient matching because full immunologicalfunctionality is maintained. Specifically, by modifying the swine donorcells, through gene editing techniques, to cause the donor cells toexpress the human recipient's MHC molecules will serve to reduceimmunological rejection of transplanted swine cells, tissues, and/ororgans, into a human recipient. This is desirable since MHC variation inthe human population is very high and having a transplanted cell,tissue, or organ that expresses MHC molecules practically identical tothe recipient will serve to decrease immunological rejection of suchtransplanted swine cells, tissues, and/or organs.

According to an aspect of the present disclosure, gene editing isperformed to knock-in HLA-E and HLA-G constructs into the swine MHCregion Class I region. According to an aspect of the present disclosure,gene editing is performed to knock-in HLA-C, HLA-E, and HLA-G constructsinto the swine MHC region Class I region. CD94/NKG2 is a heterodimerexpressed on natural killer (NK) and a small subset of T cells. Thisreceptor varies in function as an inhibitor or activator depending onwhich isoform of NKG2 is expressed. The ligand for CD94/NKG2 is HLA-E inhuman, which binds leader peptides from other class I molecules. Similarto NK cells, most CD8 T cells that express high levels of CD94co-express NKG2A, the inhibitory isoform. The engagement of thisreceptor can lead to a blocking of cytotoxicity. However, thesereceptors have also been implicated in the cell survival of both NK andCD8 T cells. The level of CD94 expression is inversely correlated withthe level of apoptosis in culture. Thus, CD94/NKG2 receptors mayregulate effector functions and cell survival of NK cells and CD8 Tcells, thereby playing a crucial role in the innate and adaptive immuneresponse to a pathogen. In certain aspects, the present disclosureincludes testing donor animals and/or xenotransplantation productrecipients for natural killer cell increase, e.g., by mass cytometry.

Other genetic modifications to swine can also decrease immunologicalrejection. For example, a number of transgenic modifications to swinehave been implemented to reduce immunogenicity and immunologicalrejection (see, e.g., Denner J, “Xenotransplantation-Progress andProblems: A Review,” J Transplant Technol Res 4(2):133 (2014)(“Denner”)), the entire disclosure of which is incorporated herein byreference). These include, but are not limited to, hCD46 (hMCP, humanmembrane cofactor), hCD55, hCD59, hCD39, thrombomodulin, heme oxygenase1, A20, HLA-E, and CD47, and combinations thereof for inhibition ofhuman complement regulation, and other modifications as set forth inDenner and herein. Further modifications have been described inUS2018/0184630, US2017/0216358, US2019/0004063, and U.S. Pat. No.9,888,673, which are incorporated herein by reference in theirentireties.

As will also be understood from the present invention, othercharacteristics of products derived from swine for xenotransplantationinvoke an increased immune response from the human body. For example,swine may carry a multitude of pathogens, including, but not limited to,Porcine Cytomegalovirus (“pCMV”), Leptospira species, arterivirus,Porcine coronavirus, Toxoplasma gondii and other pathogens. Theinventors have identified a specific group of pathogens that arecritical to exclude in order to achieve the advantages of the disclosedinvention. It is therefore an object of the present invention thatproducts derived from swine for pig to human xenotransplantationprocedures are free of the specific group of pathogens described herein.

The innate immune system, through human pattern recognition receptors(PRRs) and toll-like receptors (TLRs), detect structures located on cellsurfaces or otherwise associated with such pathogens (e.g.,pathogen-associated molecular patterns (PAMPs)), that are non-self,causing rejection of the subject xenotransplantation product. It istherefore an object of the present invention to remove, eliminate, kill,destroy, and/or otherwise neutralize, such structures from the subjectproducts to minimize or even eliminate immunological reaction and/orrejection upon xenotransplantation of such products.

It is a further object of the present invention to produce such specificpathogen free swine products from swine having one or more uniquecharacteristics (e.g., being non-wild-type genetically reprogrammed,engineered and/or modified), including, but not limited to, swine thatlack expression of surface glycan epitopes, genetically modified swine,biologically reprogrammed, and other swine as described and disclosedherein.

It is a further object of the present invention that such products beminimally manipulated. Manipulation of xenotransplantation productsbeyond their natural state (e.g., fixing in aldehyde) contributes tomaking such products non-viable. Hence, it is an object of the presentinvention that the products disclosed and described herein be minimallymanipulated, viable, live cell, and capable of making an organic unionwith the transplant recipient, including, but not limited to, inducingvascularization and/or collagen generation in the transplant recipient.

It is a further object of the present invention that such products insome instances are preserved, including, but not limited to, throughcryopreservation, in a manner that maintains viability and live cellcharacteristics of such products. It will be understood that suchproducts may also be stored as continually fresh, from harvesting totransplantation, and not cryopreserved. It is a further object of thepresent invention that such products have at least 50%, 55%, 60%, 65%,70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% mitochondrial activity after afreeze-thaw cycle prior to transplantation. It is a further object ofthe present invention that such products have at least 80%, 85%, 90%,95%, 98%, or 99% mitochondrial activity in fresh products fortransplantation. It is a further object of the present invention thatsuch products have at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85%cell viability in a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT)-reduction assay. The present invention is not limited todetection using the MTT-reduction assay and other detection assays mayalso be used. In such an exemplary assay, a level of 100% metabolicactivity is defined, e.g., as the results of MTT-reduction assay fromfresh (non-cryopreserved) tissue samples obtained from the single sourceanimal donor, which constitutes the baseline, positive control forviability of the product lot. The absence of metabolic activity (0%) isdefined as the results of MTT-reduction assay from heat-deactivated(boiling, or similar) tissue samples obtained from the single sourceanimal donor, which constitutes the baseline, negative control for theviability of product lot. Product viability is a comparison of themetabolic activity in the test article, as compared to the 100% and 0%boundary conditions described above. Industry norms and publishedreference standards support that 50% biologic activity is acceptable toprovide consistent, clinically useful materials.

It is a further object of the present invention that such products befor homologous use, i.e., the repair, reconstruction, replacement orsupplementation of a recipient's organ, cell and/or tissue with acorresponding organ, cell and/or tissue that performs the same basicfunction or functions as the donor (e.g., swine skin is used as atransplant for human skin, swine kidney is used as a transplant forhuman kidney, swine liver is used as a transplant for human liver, swinenerve is used as a transplant for human nerve and so forth).

It is a further object of the present invention that the utilization ofsuch products in xenotransplantation be performed with or without theneed to use immunosuppressant drugs or therapies which inhibit orinterfere with normal immune function. While it is knownimmunosuppressive drugs may be used to prevent rejection ofxenotransplantation products, such drugs also inhibit immune responsesagainst, for example, viral and bacterial infections, thereby placingthe recipient at risk. Xenotransplantation has typically been followedby rejection of the transplanted tissue. The rejection may be a cellularrejection (lymphocyte mediated) or humoral (antibody mediated) rejectionincluding but not limited to hyperacute rejection, an acute rejection, achronic rejection, may involve survival limiting thrombocytopeniacoagulopathy and an acute humoral xenograft reaction (AHXR). While notbeing limited by mechanism, both humoral and cellular rejectionprocesses may target MHC molecules. The human hyperacute rejectionresponse to swine glycans and proteins present on transplanted tissue isso strong that the transplant tissue is typically damaged by the humanimmune system within minutes or hours of transplant into the human.

Furthermore, different rejection mechanisms may predominate in anorgan-preferred manner. An acute or rapid humoral rejection may beginwithin minutes of transplant; an acute or rapid cellular rejection maybegin within days of the transplant. Both humoral and cellularrejections may also have a slower or chronic rejection phase; thechronic phases may occur for years. See Demetris et al. 1998“Antibody-mediated Rejection of Human Orthotopic Liver Allografts. Astudy of liver transplantation across ABO blood group barriers”, Am J.Pathol 132:489-502; Nakamura et al 1993 “Liver allograft rejection insensitized recipients. Observations in a Clinically Relevant SmallAnimal Model” Am J. Pathol. 142:1383-91; Furuya et al 1992. “PreformedLymphocytotoxic Antibodies: the Effects of Class, Titer and Specificityon Liver v Heart Allografts” Hepatology 16:1415-22; Tector et al 2001.“Rejection of Pig Liver Xenografts in Patients with Liver Failure:Implications for Xenotransplantation”, Liver Transpl pp. 82-9; hereinincorporated by reference in their entirety.

Pig cells express multiple proteins which are not found in human cells.These include, but are not limited to, α1,3-galactosyltransferase(αGal), cytidine monophosphate-N-acetylneuraminic acid hydroxylase(CMAH) and β1-4 N-acetylgalactosaminyltransferase. Antibodies to theCMAH (and Neu5GC), α-Gal, and Sda-like antigens are present in humanblood prior to implantation of xeno-tissue, and are involved in theintense and immediate antibody-mediated rejection of implanted tissue.Additionally, pig cells express multiple swine leukocyte antigens(SLAs). Unlike humans, pigs constitutively express class I and class IISLAs on endothelial cells. SLAs and HLAs share considerable sequencehomology (Varela et al 2003 J. Am. Soc. Nephrol 14:2677-2683). Anti-HLAantibodies present in human serum prior to implantation of porcinetissue cross-react with SLA antigens on porcine tissues. The SLAcross-reacting antibodies contribute to the intense and immediaterejection of the implanted porcine tissue. SLA antigens may also beinvolved with the recipient's T-cell mediated immune response. PorcineSLAs may include, but are not limited to, antigens encoded by the SLA-1,SLA-2, SLA-3, SLA-4, SLA-5, SLA-6, SLA-8, SLA-9, SLA-11 and SLA-12 loci.Porcine Class II SLAs include antigens encoded by the SLA-DQ and SLA-DRloci. See FIG. 26.

The present disclosure includes reprogramming donor animal cells so thatfull immune functionality in the donor animal is retained, but the cellsurface-expressing proteins and glycans are reprogrammed such that theyare not recognized as foreign by the human recipient's immune system.Accordingly, in contrast to prior art disclosures which called forknocking out MHCs and SLAs or inserting transgenes into the animal'sgenomes, the present disclosure relates to reprogramming the animal'sgenome by reprogramming only discrete and small portions so that theanimal retains a functional immune system, but the animal's reprogrammedcells do not express cell surface-expressing proteins and glycans thatelicit attack by the human recipient's immune system.

For immunogenic reprogramming using CRISPR, a guide RNA first binds to acomplementary sequence of genomic DNA at the target site. Cas9 thenmakes a double-strand break (DSB) at the targeted site. However, thecleavage of the target is contingent upon the initial binding of thenuclease to a protospacer adjacent motif (PAM) 3-4 nucleotidesdownstream of the cut site. The PAM motif for SpCas9 is 5′-NGG-3′ (withN signifying any nucleotide). Different types of CRISPR nucleasesrecognize different PAM sequences. Once a DSB is made, the cell willactivate machinery to repair the cut site. It is during this repair whenedits to the genome take place.

In some aspects, knockouts are achieved so as to make mutations thatrender a gene inoperative. In eukaryotic cells, DSBs are often repairedthrough non-homologous end joining (NHEJ), a quick-fix repair mechanismthat involves ligating the ends of each DNA strand together. Prone toerror, NHEJ often results in the insertion or deletion of nucleotides(called indels) at the break site. Indels in protein-coding regions thatare not multiples of three induce frameshift mutations. Because thereading frame of the gene is altered, these mutations often lead to lossof gene function (i.e., knockout, no functional protein is made). Thistype of alteration can be used for a variety of loss-of-functionapplications.

In some aspects, knock-ins are achieved so as to insert a foreigngenetic sequence.

Importantly, persons of ordinary skill are now fully enabled togenetically modify cells with commercially available CRISPR kits as wellas via a multitude of commercial service organizations that providedesign, consulting, and laboratory services with guaranteed results forany desired knock out or knock in experiments using CRISPR technology.Thus, persons skilled in the art can use the present disclosure to makeand use the disclosed invention without undue experimentation.

In certain aspects, the present disclosure includes sequencing therecipient's HLA/MHC gene, preparing template HLA/MHC sequences,preparing CRISPR-Cas9 plasmids, e.g., using polymerase chain reaction,cloning template HLA/MHC sequences into the plasmids, determining CRISPRcleavage sites at the HLA/MHC locus in the swine cells, cloning gRNAsequences into one or more CRISPR-Cas9 plasmids, administeringCRISPR-Cas9 plasmids into the swine cells, performing CRIPSR/Cas9cleavage at the MHC locus of the swine cells, replacing the HLA/MHClocus in the swine cells with one or more template HLA/MHC sequencesmatching the recipient's sequenced HLA/MHC genes. In the Cas9 system,many Cas9-like nucleases were developed given the natural diversity ofbacterial CRISPR systems. Cpf1, a putative Class 2 CRISPR effector,mediates target DNA editing with distinct features from Cas9. Incontrast to Cas9 which generates blunt ends, Cpf1 generates a 5-ntstaggered cut with a 5′ overhang, which is particularly advantageous infacilitating a NHEJ-based gene insertion (knock-in) into a genome. Ahybrid enzyme combining the Cas9-nickase and PmCDA1, anactivation-induced cytidine deaminase could perform targeted nucleotidesubstitution (C-U) without the use of template DNA, providing a novelroute for point mutation. A CRISPR system (Cas13a) that targets RNA hasalso been developed recently. A structure-guided endonuclease (SGN)consisting of flap endonuclease-1 that recognizes the 3′ flap structureand the cleavage domain of Fok I, which cleaves DNA strands, may also beused. A guide DNA complementary to the target with an unpaired 3′ end isneeded to form a 3′ flap structure. SGN recognizes and cleaves thetarget DNA on the basis of the 3′ flap structure of a double-flapcomplex formed between the target and the guide DNA. The SGN offers astrategy for a structure-based recognition, capture, and editing of anydesired target DNA, thereby expanding the toolkit for geneticmodification. In certain aspects, the present disclosure furtherincludes sequencing cells of the swine after performing the HLA/MHCreplacement steps in order to determine if the HLA/MHC sequences in theswine cells have been successfully replaced. In certain aspects, thepresent disclosure further includes transplanting one or more cells,tissues, and/or organs from the HLA/MHC sequence-replaced swine into ahuman recipient. In certain aspects, the present disclosure furtherincludes breeding HLA/MHC sequence-replaced swine for at least onegeneration, or at least two generations, before their use as a sourcefor live tissues, organs and/or cells used in xenotransplantation.

In certain aspects, known human sequence information is available, e.g.,in the IPD-IMGT/HLA database or library (available atebi.ac.uk/ipd/imgt/hla/) and the international ImMunoGeneTicsInformation System® (available at imgt.org). Nomenclature for such genesis illustrated in FIG. 20. For example, HLA-A1, B8, DR17 is the mostcommon HLA haplotype among Caucasians, with a frequency of 5%. Further,maps of human genomic information to animal genomic information areavailable. For example, as shown in FIG. 23 and FIG. 24, maps of thehuman and swine major histocompatibility complex class I and claim IIregions are known and can be used to reprogram swine cells according tothe present disclosure so as to retain the donor animal's immunefunction while reducing or eliminating reactivity of the humanrecipient's body to the xenotransplanted products from the donor animal.Thus, the disclosed method can be performed using the known MHC/HLAsequence information.

In certain aspects, the present disclosure includes a biological productfor clinical xenotransplantation derived from a non-wild type,genetically engineered, swine, wherein said swine has a genome with adisrupted alpha-1,3 galactosyltransferase gene, and wherein a cell fromthe swine has been genetically modified such that it expresses a majorhistocompatibility complex of a recipient of said biological product.

The above and other various aspects and aspects are described below withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form partof the disclosure, help illustrate various aspects of the presentinvention and, together with the description, further serve to describethe invention to enable a person skilled in the pertinent art to makeand use the aspects disclosed herein. In the drawings, like referencenumbers indicate identical or functionally similar elements.

FIG. 1 illustrates a source animal facility and corresponding designatedpathogen free facilities, animals, and herds in accordance with thepresent invention.

FIG. 2 illustrates a method for preparing a skin product in accordancewith the present invention.

FIG. 3 illustrates a combination skin product in accordance with thepresent invention.

FIG. 4 illustrates an extracorporeal liver filter and circuit inaccordance with the present invention.

FIG. 5A depicts porcine split-thickness skin grafts at wound sites 1, 2,3, and 4, respectively from left to right at POD-12. FIG. 5B depictsporcine split-thickness skin grafts at wound site 4 at POD-12 (left) andPOD-14 (right).

FIG. 6A graphs MTT reduction assays fresh vs. cryopreserved (7 years) inporcine tissue samples showing no statistical difference. FIG. 6B graphsMTT reduction assays heat deactivated vs. cryopreserved (7 years) inporcine tissue samples showing a statistically significant different inquantity of formazan produced.

FIG. 7 shows histological images of H&E stained sections from thecryopreserved grafts and stored for 7 years show viable normal skin withintact epidermis. The blood vessels and adnexal structures were alsonormal. No distinguishable differences could be seen at a histologicallevel based on duration of storage. From Left to Right (Duration ofStorage): 15 minutes, 7 years, 7 years.

FIG. 8 depicts longitudinal progression of porcine split-thickness skingraft used as a temporary wound closure in treatment of full-thicknesswound defects in a non-human primate recipient. Left: POD-0,xenotransplantation product at Wound Site 2. Right: POD-30, samexenotransplantation product at Wound Site 2.

FIG. 9A depicts POD-15. H&E, H&E, high power image depicts tissueviability with surface and follicular epithelial necrosis. FIG. 9Bdepicts POD-22 H&E, high power image demonstrating residual autograft(asterisks) with good overall viability. No surface epithelium and somesurface necrosis noted, along with extensive fibrosis with infiltrationinto the autograft (arrows).

FIG. 10 shows POD-30 histological images for: Top, Center: H&E, Lowpower image of wound site depicts complete epithelial coverage. Dottedline surrounds the residual xenotransplantation product.

FIG. 11A graphs the total serum IgM ELISA (μg/mL) for all four subjects(2001, 2002, 2101, 2102) during the course of the study. FIG. 11B graphsthe total serum IgG ELISA (μg/mL) for all four subjects (2001, 2002,2101, 2102) during the course of the study.

FIG. 12A graphs systemic concentrations of soluble CD40L as measured byLuminex 23-plex at POD-0, POD-7, POD-14, POD-21, and POD-30. FIG. 12Bgraphs systemic concentrations of TGF-alpha as measured by Luminex23-plex at POD-0, POD-7, POD-14, POD-21, and POD-30. FIG. 12C graphssystemic concentrations of IL-12/23 (p40) as measured by Luminex 23-plexat POD-0, POD-7, POD-14, POD-21, and POD-30.

FIG. 13 schematically illustrates Human MHC Class I and Class IIisotypes.

FIG. 14 schematically illustrates codominant expression of HLA genes andthe position of HLA genes on human chromosome 6.

FIG. 15 is a table listing numbers of serological antigens, proteins,and alleles for human MHC Class I and Class II isotypes.

FIG. 16 schematically illustrates HLA Class I and Class II on thesurface of a cell.

FIG. 17 shows the structure of MHC Class I (A) and class II proteins(B). The two globular domains furthest from the plasma membrane thatform the peptide binding region (PBR) are shaded in blue. The twoIg-like domains, including the β2-microglobulin, are shaded in grey.

FIG. 18 schematically illustrates HLA Class I on the surface of a cell.

FIG. 19 shows the Human Leukocyte Antigen Complex (HLA). The HLA genesare the most polymorphic in the genome. The allelic diversity of the HLAclass I and class II loci is extensive, with >13,000 alleles described.

FIG. 20 illustrates nomenclature of HLA alleles. Each HLA allele namehas a unique number corresponding to up to four sets of digits separatedby colons. The length of the allele designation is dependent on thesequence of the allele and that of its nearest relative. All allelesreceive at least a four digit name, which corresponds to the first twosets of digits, longer names are only assigned when necessary. Thedigits before the first colon describe the type, which often correspondsto the serological antigen carried by an allotype. The next set ofdigits are used to list the subtypes, numbers being assigned in theorder in which DNA sequences have been determined. Alleles whose numbersdiffer in the two sets of digits must differ in one or more nucleotidesubstitutions that change the amino acid sequence of the encodedprotein. Alleles that differ only by synonymous nucleotide substitutions(also called silent or non-coding substitutions) within the codingsequence are distinguished by the use of the third set of digits.Alleles that only differ by sequence polymorphisms in the introns, or inthe 5′ or 3′ untranslated regions that flank the exons and introns, aredistinguished by the use of the fourth set of digits.

FIGS. 21A-21B show a string model for TCR-pMHC complex from Tsurui etal., General Med 2013, 2:1. In this simplified model, CDR1 and CDR2 ofTCRs mainly interact with helices running along both sides of MHCmolecules, between which the presented peptide is located. In this case,CDR3 (LKVEGTRVY) interacts with a presented peptide (LDIRASELT) so as toform a ladder with 9 rungs (L-L, K-D, V-I, E-R, G-A, T-S, R-E, V-L,Y-T). For simplicity, only the interaction between CDR3 and thepresented peptide is considered (SI 1). (FIG. 21A) AA contact energieswere assigned respectively to these rungs (AA pairs) by the M-J matrix,and the binding energy between CDR3 and the presented peptide could becalculated by summing these values. (FIG. 21B) Actual 3-dimensionalstructure of a TCR-pMHC complex (PDBID: 1A07) is shown. Both CDR3 loopscomprise a and f3 chains running across rather than parallel to thepresented peptide. CDR2 mainly interacts with helices, whereas CDR1interacts with both MHC helix and presented peptide. The TCR-pMHCbinding mode also varies widely.

FIG. 22 schematically illustrates a T Cell Receptor (TCR) binding MHCclass I and a peptide.

FIG. 23 is a comparative genomic organization of the human and swine MHCClass I region.

FIG. 24 is a comparative genomic organization of the human and swine MHCClass II region.

FIG. 25 shows a physical map of the SLA complex. Black boxes: locicontaining MHC-related sequences. White boxes: loci without MHC-relatedsequences. From the long arm to the short arm of the chromosome, theorder of the regions is class II (II), class III (III) and class I (I).

FIG. 26 shows the schematic molecular organization of the SLA genes.Exons are represented by the gray ovals and introns by lines. Genelength is approximate to that found for the Hp-1.1 genome sequence.

FIG. 27 schematically illustrates a Cytotoxic T Cell (CD8+)-Target CellInteraction.

FIG. 28 schematically illustrates a Cytotoxic T Cell (CD4+)-Target CellInteraction.

FIG. 29 shows a shipping process of a xenotransplantation product.

FIG. 30 shows a cryovial used to store a xenotransplantation product.

FIG. 31 shows a secondary closure or container system for storing axenotransplantation product at temperatures below ambient temperature,including, but not limited to, −150 degrees Celsius and othertemperatures.

FIG. 32 shows a Clinical Wound Assessment Scale in accordance with oneaspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While aspects of the subject matter of the present disclosure may beembodied in a variety of forms, the following description is merelyintended to disclose some of these forms as specific examples of thesubject matter encompassed by the present disclosure. Accordingly, thesubject matter of this disclosure is not intended to be limited to theforms or aspects so described.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise.

The term “treating” or “treatment” as used herein and as is wellunderstood in the art, means an approach for obtaining beneficial ordesired results, including clinical results. Beneficial or desiredclinical results can include, but are not limited to, alleviation oramelioration of one or more symptoms or conditions, diminishment ofextent of disease, stabilizing (i.e. not worsening) the state ofdisease, delaying or slowing of disease progression, amelioration orpalliation of the disease state, diminishment of the reoccurrence ofdisease, and remission (whether partial or total), whether detectable orundetectable. “Treating” and “treatment” can also mean prolongingsurvival as compared to expected survival if not receiving treatment. Inaddition to being useful as methods of treatment, the methods describedherein may be useful for the prevention or prophylaxis of disease.

Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to include allthe individual numerical values or sub-ranges encompassed within thatrange as if each numerical value and sub-range is explicitly recited. Asan illustration, a numerical range of “about 0.01 to 2.0” should beinterpreted to include not only the explicitly recited values of about0.01 to about 2.0, but also include individual values and sub-rangeswithin the indicated range. Thus, included in this numerical range areindividual values such as 0.5, 0.7, and 1.5, and sub-ranges such as from0.5 to 1.7, 0.7 to 1.5, and from 1.0 to 1.5, etc. Furthermore, such aninterpretation should apply regardless of the breadth of the range orthe characteristics being described. Additionally, it is noted that allpercentages are in weight, unless specified otherwise.

In understanding the scope of the present disclosure, the terms“including” or “comprising” and their derivatives, as used herein, areintended to be open ended terms that specify the presence of the statedfeatures, elements, components, groups, integers, and/or steps, but donot exclude the presence of other unstated features, elements,components, groups, integers and/or steps. The foregoing also applies towords having similar meanings such as the terms “including”, “having”and their derivatives. The term “consisting” and its derivatives, asused herein, are intended to be closed terms that specify the presenceof the stated features, elements, components, groups, integers, and/orsteps, but exclude the presence of other unstated features, elements,components, groups, integers and/or steps. The term “consistingessentially of”, as used herein, is intended to specify the presence ofthe stated features, elements, components, groups, integers, and/orsteps as well as those that do not materially affect the basic and novelcharacteristic(s) of features, elements, components, groups, integers,and/or steps. It is understood that reference to any one of thesetransition terms (i.e. “comprising,” “consisting,” or “consistingessentially”) provides direct support for replacement to any of theother transition term not specifically used. For example, amending aterm from “comprising” to “consisting essentially of” would find directsupport due to this definition.

As used herein, the term “about” is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint. The degree offlexibility of this term can be dictated by the particular variable andwould be within the knowledge of those skilled in the art to determinebased on experience and the associated description herein. For example,in one aspect, the degree of flexibility can be within about ±10% of thenumerical value. In another aspect, the degree of flexibility can bewithin about ±5% of the numerical value. In a further aspect, the degreeof flexibility can be within about ±2%, ±1%, or ±0.05%, of the numericalvalue.

Generally, herein, the term “or” includes “and/or.”

As used herein, a plurality of compounds or steps may be presented in acommon list for convenience. However, these lists should be construed asthough each member of the list is individually identified as a separateand unique member. Thus, no individual member of such list should beconstrued as a de facto equivalent of any other member of the same listsolely based on their presentation in a common group without indicationsto the contrary.

The present disclosure provides a continuous manufacturing process for axenotransplantation product that has reduced immunogenicity, reducedantigenicity, increased viability, increased mitochondrial activity, aspecifically required pathogen profile, and unexpectedly long shelf-lifein xenotransplantation tissues subject to cryopreservation. Thecontinuous manufacturing process is surprisingly and unexpectedlyeffective in avoiding hyperacute rejection, delayed xenograft rejection,acute cellular rejection, chronic rejection, cross-species transmissionof diseases, cross-species transmission of parasites, cross-speciestransmission of bacteria, cross-species transmission of fungi,cross-species transmission of viruses. The continuous manufacturingprocess is surprisingly and unexpectedly effective in creating a closedherd in which the donor animals survive normally without detectablepathological changes.

Source Animal Facility (“SAF”)

Referring to FIG. 1, a barrier source animal location, including, butnot limited to, a Source Animal Facility (“SAF”) 100, that can be usedfor the housing, propagation, maintenance, care and utilization of aclosed colony swine, including a closed colony that is designatedpathogen free (“DPF”) (“DPF Closed Colony”) 102, is shown. As containedherein, the SAF has positive pressure, biocontainment characteristics isoperated under specific isolation-barrier conditions.

As described herein, the DPF Closed Colony 102 is comprised of sourceanimals maintained and propagated for harvesting various biologicalproducts for use in human xenotransplantation and other therapies,wherein such products have reduced bioburden and demonstrate reducedimmunogenicity resulting from xenotransplantation and other therapeuticprocedures. In some aspects, xenotransplantation products of the presentdisclosure are less immunogenic than a xenotransplantation product madefrom conventional Gal-T knockout swine, from conventional tripleknockout swine, from transgenic swine, from wild-type animals, and/orallograft. For example, as shown in Examples 1 and 2, biologicalproducts made according to the present disclosure provided unexpectedlyhigh clinical benefit when using a single knockout pig as the donoranimal in that, despite the presence of Neu5Gc and porcine B4GALNT2, thebiological product made according to the present disclosure had lessimmunogenicity than allograft, vascularized, and was resistant torejection for the entire duration of the study period.

As further described herein, the SAF 100 and each of its accompanyingareas (e.g., rooms, suites or other areas) can be utilized to house andmaintain source animals from which biological products are harvestedand/or processed. The SAF 100 and its areas are designed to minimize andeliminate the potential for contamination of the harvested and/orprocessed biological products and cross-contamination between suchproducts.

Within the SAF 100, in some aspects, utilized animal areas areventilated. For example, animal areas are ventilated with highefficiency particulate air (HEPA)-filtered fresh air from the roof ofthe building, for example, having at least 10-15 air changes per hour.Additionally, one or more laminar flow hoods (e.g., Class II Type A2Laminar Airflow Biosafety Cabinets) are utilized in the SAF rooms,including in a xenotransplantation drug processing suite to providingadditional ventilation to minimize or eliminate cross contamination.

In some aspects, utilized areas are also temperature controlled andmonitored. For example, the areas are heated and cooled to maintaintemperature within the range specified by, for example, the Guide forthe Care and Use of Laboratory Animals. Utilized animal holding roomsare also alarmed and centrally monitored for high or low temperatures,and staff are notified immediately if temperatures are beyond requiredtemperature.

In some aspects, the SAF 100 has multiple levels of containment for thesource animals. For example, source animals are contained in a primarylevel of containment consisting of pens and cages which are secured bystainless steel latches. With respect to secondary level of containment,functionally designated areas (e.g., rooms, suites or other areas) canhave latched inner doors, and an ante-room with card-controlled accessto a hallway. A tertiary level of containment can include outsideperimeter fencing.

The entire SAF is located within a single building. Primary entrance isthrough a single door via programmable identification (ID) card. Allother external doors are alarmed, remain locked, and are for emergencyuse only.

Security is also a consideration to ensure security of the SAF 100 ingeneral, and to control individuals entering the SAF 100 to minimize therisk of outside contaminants entering the SAF 100 and reaching thesource animals. Therefore, in one aspect, the primary entrance to theSAF 100 is through a single door 116 via programmable identification(ID) card 118. All other external doors 120 are alarmed, remain locked,and are for emergency use only.

It will be understood that the SAF 100 and its features as disclosedherein are set out as examples, and it will be further understood thatother facilities with various features can also be utilized to performthe methods and produce the products disclosed herein.

In some aspects, the SAF 100 animal program is licensed and/oraccredited and overseen, evaluated and operated by a team of highlyexperienced, professional staff. For example, the program is registeredand/or accredited with the USDA Animal and Plant Health InspectionService (as a licensed animal research facility), National Institute ofHealth (NIH) Office of Laboratory Animal Welfare (OLAW) (confirmingcompliance with Public Health and Safety (PHS) regulations, Associationfor Assessment and Accreditation of Laboratory Animal Care (AAALAC)(with veterinary care of the source animals housed at the SAF under thedirection of an attending veterinarian), and other federal, state andlocal regulatory authorities.

In some aspects, to ensure the welfare of the source animals, SAFpersonnel, and caretakers of source animals adhere to procedures foranimal husbandry, tissue harvesting, and termination of animals that areapproved by an appropriate Institutional Animal Care and Use Committee,in accordance with the Animal Welfare Act (7 U.S.C. 2131, et seq.),accredited by the AAALAC, and in compliance of the standards as setforth in the Guide for the Care and Use of Laboratory Animals.

In some aspects, caretakers have extensive training and experience inhandling and caring for the source animals being managed in accordancewith the present invention. For example, each caretaker undergoes adocumented training program covering the standard operating proceduresgoverning handling and care of these source animals, and be skilled inmaking daily health assessments and insuring prompt care is directed toany animal in need. In addition, the caretakers can be trained inscrubbing and gowning procedures prior to entry into the isolation areas(e.g., rooms, suites or other areas) as described herein, and under amedical surveillance program to ensure staff health and the health ofthe source animals.

To minimize and eliminate contamination risk to the SAF, any personnelor visitors entering the SAF wear personnel protective equipment orchange into facility dedicated clothing and footwear before entry intoany containment areas. Visitors who wish to enter animal areas must nothave had any contact with live swine for at least 24 hours preceding thevisit or must shower at the facility prior to entry.

It will be understood that the approaches and procedures set forthherein are examples as to how to ensure contamination does not reach thesource animals within SAF 100. It will be further understood that amultitude of approaches can also be utilized to achieve a designatedpathogen free environment for source animals.

Source Animals

In some aspects, as described herein, swine can be utilized as sourceanimals. As used herein, unless otherwise specified, the terms “swine,”“pig” and “porcine” are generic terms referring to the same type ofanimal without regard to gender, size, or breed. It will be understoodthat any number of source animals could be utilized in accordance withthe present invention, including, but not limited to, pigs, non-humanprimates, monkeys, sheep, goats, mice, cattle, deer, horses, dogs, cats,rats, mules, and any other mammals. Source animals could also includeany other animals including, but not limited to, birds, fish, reptiles,and amphibians. It will be understood that the term “disrupting” or“disrupt” or “disrupted” or like terms as used herein can include anyand/or all modifications to a gene and related materials, including, butnot limited to, removing, editing, silencing, modifying, reprogramming,immunogenomic reprogramming, altering, changing, engineering, knockingin, adding, knocking out, and/or any or all other such modifications.

Swine Lacking Expression of Extracellular Surface Glycan Epitopes

In some aspects, the swine source animals are genetically modified(i.e., non-wild-type). For example, in some aspects, the swine include“knockout” and/or “knock-in” swine having one or more characteristics ofswine disclosed in U.S. Pat. No. 7,795,493 (“Phelps”), the entiredisclosure of which is incorporated herein by reference. Such swine lackactive (and/or have disrupted) α-(1,3) galactosyl epitopes responsiblefor hyperacute rejection in humans upon transplantation. Multiplemethods of production of knockout/knock-in swine are disclosed in Phelpsincluding: the inactivation of one or both alleles of the alpha-1,3-GTgene by one or more point mutations (for example by a T-to-G pointmutation at the second base of exon 9) and/or genetic targeting eventsas disclosed at col. 9, line 6 to col. 10, line 13; col. 21, line 53 tocol. 28, line 47; and col. 31, line 48 to col. 38, line 22. The creationof such swine through the described methods, and/or the utilization ofsuch swine and progeny following creation, can be employed in thepractice of the present invention, including, but not limited to,utilizing organs, tissue and/or cells derived from such swine.

Similarly, in other aspects, the swine source animals include “knockout”and “knock-in” swine having one or more characteristics of swinedisclosed in U.S. Pat. No. 7,547,816 (“Day”), the entire disclosure ofwhich is incorporated herein by reference. Such swine also lack active(and/or have disrupted) α-(1,3) galactosyl epitopes responsible forhyper-acute rejection in humans upon transplantation. Multiple methodsof production of knockout/knock-in swine are disclosed in Day including:enucleating an oocyte, fusing the oocyte with a porcine cell having anon-functional alpha-1,3-GT gene, followed by implantation into asurrogate mother, as described more fully at col. 4, line 61 to col. 18,line 55. The creation of such swine through the described methods,and/or the utilization of such swine and progeny following creation, canbe employed in the practice of the present invention, including, but notlimited to, utilizing organs, tissue and/or cells derived from suchswine.

Similarly, in other aspects, the swine source animals include GGTA Null(“knockouts” and “knock-ins”) swine having one or more characteristicsof swine disclosed in U.S. Pat. No. 7,547,522 (“Hawley”), the entiredisclosure of which is incorporated herein by reference. Such swine alsolack active (and/or have disrupted) α-(1,3) galactosyl epitopesresponsible for hyper-acute rejection in humans upon transplantation. Asdisclosed in Hawley, production of knockout/knock-in swine includesutilizing homologous recombination techniques, and enucleating oocytesfollowed by fusion with a cell having a non-functional alpha-1,3-GT geneand implantation into a surrogate mother (as disclosed more fully atcol. 6, line 1 to col. 14, line 31). The creation of such swine throughthe described methods, and/or the utilization of such swine and progenyfollowing creation, can be employed in the practice of the presentinvention, including, but not limited to, utilizing organs, tissueand/or cells derived from such swine.

In yet other aspects, the swine source animals include swine and swinethat lack active (and/or have disrupted) α-(1,3) galactosyl epitopeshaving one or more characteristics of swine as described in U.S. Pat.No. 9,883,939 (“Yamada”), the entire disclosure of which is incorporatedby reference herein. In certain aspects, the swine source animals foruse or modification in accordance with the present disclosure includethe swine having one or more characteristics of swine described in U.S.2018/0184630 (Tector, III), the disclosure of which is incorporated byreference herein in its entirety. The creation of such swine through thedescribed methods, and/or the utilization of such swine and progenyfollowing creation, can be employed in the practice of the presentinvention, including, but not limited to, utilizing organs, tissueand/or cells derived from such swine.

In yet other aspects, swine source animals include the swine having oneor more characteristics of swine disclosed in U.S. Pat. No. 8,106,251(Ayares), U.S. Pat. No. 6,469,229 (Sachs), U.S. Pat. No. 7,141,716(Sachs), each of the disclosures of which are incorporated by referenceherein. The creation of such swine through the described methods, and/orthe utilization of such swine and progeny following creation, can beemployed in the practice of the present invention, including, but notlimited to, utilizing organs, tissue and/or cells derived from suchswine.

In some aspects, the swine can originate from one or more highly inbredherds of pigs (whether genetically modified or not (i.e., wild-type))with a co-efficient of inbreeding of 0.50 or greater. A highercoefficient of inbreeding indicates the products derived from the sourceanimals may have more consistent biological properties for use inpig-to-human xenotransplantation (e.g., a coefficient of inbreeding of0.80 or greater in one aspect). Coefficients of inbreeding for animalsare disclosed in Mezrich et al., “Histocompatible Miniature Swine: AnInbred Large-Animal Model,” Transplantation, 75(6):904-907 (2003). Anexample of a highly inbred herd of swine includes miniature swinedescendant from the miniature swine disclosed in Sachs, et al.,“Transplantation in Miniature Swine. I. Fixation of the MajorHistocompatibility Complex,” Transplantation 22:559 (1976), which is ahighly inbred line possessing reasonable size matches particularly fororgans eventually utilized for clinical transplantation. The creation ofsuch swine through the described methods, and/or the utilization of suchswine and progeny following creation, can be employed in the practice ofthe present invention, including, but not limited to, utilizing organs,tissue and/or cells derived from such swine.

Source animals can also include animals swine that lack active (and/orhave disrupted) alpha-1,3-galactosyltransferase, Neu5Gc, andβ1,4-N-acetylgalactosaminyltransferase as described in U.S. PatentPublication No. US2017/0311579 (Tector), the entire disclosure of whichis incorporated herein by reference. The creation of such swine throughthe described methods, and/or the utilization of such swine and progenyfollowing creation, can be employed in the practice of the presentinvention, including, but not limited to, utilizing organs, tissueand/or cells derived from such swine.

Immunogenomic Reprogrammed Swine Lacking Expression of ExtracellularSurface Glycan Epitopes

As used herein “immunogenomic reprogramming” includes replacing,silencing, altering or disrupting conserved genetic material of a donoranimal's genome through, for example, the use of site-specificendonucleases for targeted manipulation of a donor swine's genome. Thegenetic modification can be made utilizing known genome editingtechniques, such as zinc-finger nucleases (ZFNs), transcriptionactivator-like effector nucleases (TALENs), adeno-associated virus(AAV)-mediated gene editing, and clustered regular interspacedpalindromic repeat Cas9 (CRISPR-Cas9). These programmable nucleasesenable the targeted generation of DNA double-stranded breaks (DSB),which promote the upregulation of cellular repair mechanisms, resultingin either the error-prone process of non-homologous end joining (NHEJ)or homology-directed repair (HDR), the latter of which can be used tointegrate exogenous donor DNA templates. In one aspect, certain regionsof the donor swine's genome are reprogrammed including, but not limitedto, the MHC regions of the donor swine that arehomologous/analogous/orthologous to the MHC regions of a human. Forexample, according to one non-limiting aspect, a pig's genome may beimmunogenomically reprogrammed to express HLA-DQ (αβ) instead of SLA-DQ.Identification of corresponding regions between pigs and humans can befound in the literature including, for example, in Ando et al.Immunogenetics (2005) 57:864-873; Lunney, J., “Molecular genetics of theswine major histocompatibility complex, the SLA complex,” Developmentaland Comparative Immunology 33: 362-374 (2009); Shigenari et al.,Immunogenetics (2004) 55:696-705; Gao et al., Developmental andComparative Immunology, (2014) 45:87-96; Bentley et al., TissueAntigens, (2009) 74, 393-403, each of which is incorporated herein byreference in its entirety for all purposes including, but not limitedto, genetic information, sequences, and mapping.

Such “immunogenomic reprogramming,” as described herein, does not createtransgenic characteristics in the donor animal since the conservedregion or regions of the donor animal genome that are reprogrammed arenative and naturally occurring within the donor animal. This iscontrasted with transgenic animals which have genomes that have beenmodified to introduce non-native genes from a different species ofanimal (for example, but not limited to, swine having or expressinghCD46-human membrane cofactor protein, MCP; hCD55-humandecay-accelerating factor, DAF and other human genes set forth in inTable 1 herein and otherwise known in the art).

In some aspects an immunogenomically reprogrammed swine lackingexpression of extracellular surface glycan epitopes is provided. In someaspects, the source animals can include swine whose genomes, throughgenetic modification, include the removal ofalpha-1,3-galactosyltransferase (single knockout) plus immunogenomicreprogramming to modify expression of MHC as described herein. In otheraspects, the source animals can also include swine whose genomes,through genetic modification, include the removal ofalpha-1,3-galactosyltransferase and Neu5Gc (double knockout), plusimmunogenomic reprogramming to modify expression of MHC as describedherein. In yet other aspects, the source animals can also include swinewhose genomes, through genetic modification, include the removal ofalpha-1,3-galactosyltransferase, Neu5Gc, andβ1,4-N-acetylgalactosaminyltransferase (triple knockout), plusimmunogenomic reprogramming to modify expression of MHC as describedherein. In yet other aspects, source animals can also include animalswhose genome expresses one or more specific MHC molecules of the humanrecipient or a known human sequence, as described herein.

In some aspects, the immunogenomic reprogramming results in MHCexpression, non-expression, or modulated expression in the source animalas described herein. For these additional immunogenomic reprogrammedaspects, three general approaches can be employed to createhypoimmunogenic tolerant donor cells. These approaches are complementaryand synergistic to achieving such a hypoimmunogenic tolerant donor cellfor xenotransplantation which is distinct from “downstream” approachutilized by others in the xenotransplantation space as described herein.

In a first approach, the present invention utilizes immunogenomicreprogramming to reduce or eliminate MHC-I (Class A) components to avoidprovocation of natural cellular mediated immune response by therecipient. In another aspect, exon regions in the donor animal (e.g.,swine) genome corresponding to exon regions of HLA-A and HLA-B aresilenced, wholly removed, or knocked-out of the genome of the donoranimal. In another aspect, exon regions in the donor animal (e.g.,swine) genome corresponding to exon regions of HLA-A and HLA-B aresilenced, wholly removed, or knocked-out of the genome of the donoranimal and exon regions in the donor animal (e.g., swine) genomecorresponding to exon regions of HLA-C may be modulated, e.g., reduced.In one aspect, the present disclosure includes silencing, knocking out,or causing the minimal expression of source animal'shomologous/analogous/orthologous HLA-C (as compared to how such would beexpressed without such immunogenomic reprogramming). In another aspect,the immunogenomic reprogramming includes the swine donor cell to havemodulatory expression of Class II Major Histocompatibility ComplexTransactivator (CIITA) (to affect the alternate expression of HLA-C inthe source animal while retaining immunological function of the sourceanimal).

In an additional or alternative approach, the present disclosureincludes reprogramming, or leveraging the inhibitory and co-stimulatoryeffects of the MHC-I (Class B) molecules. Specifically, the presentdisclosure includes a process that “finds and replaces” portions of thedonor animal genome corresponding to portions of the HLA gene, e.g., tooverexpress HLA-G where possible, retaining and overexpressing portionscorresponding to HLA-E, and/or “finding and replacing” portionscorresponding to HLA-F. As used herein, the term “find and replace”includes identification of the homologous/analogous/orthologousconserved genetic region and replacement of the section or sections withthe corresponding human components through gene editing techniques.Another aspect includes finding and replacing the beta-2 microglobulinprotein which is expressed in HLA-A, -B, -C, -E, -F, and -G.Homologous/analogous/orthologous conserved cytokine mediating complementinhibiting or otherwise immunomodulatory cell markers, or surfaceproteins, that would enhance the overall immune tolerance atdonor-recipient cellular interface. In certain aspects, hCD55 may beknocked in in combination with any of aspects disclosed herein. Incertain aspects, hCD46 may be knocked in in combination with any ofaspects disclosed herein.

In a third approach, the present invention utilizes “find and replace”in order to express or overexpress specific ligands and otherimmunomodulatory molecules to create a localized environment of immunesuppression in a region proximate to the donor-recipient cell interfacein the manner exhibited by trophoblasts and placental cells in theregion of the decidua. Whereby, donor cells would have the ability toinduce apoptosis of T cells to include, but not be limited to, CD8+ Tcells and NK cells and have a tolerogenic impact on TRegs and CD4+ Tcells. These include, but are not limited to, Fas-L, TRAIL, PDL-1 (deathligand), and PDL-2.

In certain aspects, the present disclosure includes knocking-out:SLA-11; SLA-6,7,8; SLA-MIC2; and SLA-DQA; SLA-DQB1; SLA-DQB2, andknocking-in: HLA-C; HLA-E; HLA-G; and HLA-DQ. In certain aspects, thepresent disclosure includes knocking-in HLA-C, HLA-E, HLA-G. In certainaspects, the present disclosure includes knocking-out: swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, andknocking-in: HLA-C, HLA-E, and HLA-G. In certain aspects, the presentdisclosure includes knocking-out: swine genes corresponding to HLA-A,HLA-B, HLA-C, HLA-F, DQ, and DR, and knocking-in: HLA-C, HLA-E, HLA-G,HLA-F, and DQ. In certain aspects, expression of HLA-C may be modulated,e.g., reduced. In certain aspects, beta-2 microglobulin may be knockedin in combination with any of aspects disclosed herein. In certainaspects, hCD55 may be knocked in in combination with any of aspectsdisclosed herein. In certain aspects, hCD46 may be knocked in incombination with any of aspects disclosed herein. In certain aspects,the present disclosure includes overexpression of one or moreapoptosis-inducing ligands (e.g., FasL, TRAIL, Programmed death-ligand 1(PD-L1), Programmed death-ligand 2 (PD-L2)) to attenuate the T cellResponse in combination with any of aspects disclosed herein. In certainaspects, the present disclosure includes any combination of theforegoing genetic modifications in combination with a single, double, ortriple-knockout of swine surface glycan epitopes. In certain aspects,the present disclosure does not involve knocking-out genes coding forPERV-A, PERV-B, and/or PERV-C.

In certain aspects, expression of HLA-C may be modulated, e.g., reduced.In certain aspects, beta-2 microglobulin may be knocked in incombination with any of aspects disclosed herein. In certain aspects,hCD55 may be knocked in in combination with any of aspects disclosedherein. In certain aspects, hCD46 may be knocked in in combination withany of aspects disclosed herein. In certain aspects, the presentdisclosure includes overexpression of one or more apoptosis-inducingligands (e.g., FasL, TRAIL, Programmed death-ligand 1 (PD-L1),Programmed death-ligand 2 (PD-L2)) to attenuate the T cell Response incombination with any of aspects disclosed herein. In certain aspects,the present disclosure includes any combination of the foregoing geneticmodifications in combination with a single, double, or triple-knockoutof swine surface glycan epitopes.

In certain aspects, the present disclosure includes knocking-in HLA-C,HLA-E, HLA-G. In certain aspects, the present disclosure includesknocking-out: swine genes corresponding to HLA-A, HLA-B, HLA-C, HLA-F,DQ, and DR, and knocking-in: HLA-C, HLA-E, and HLA-G. In certainaspects, the present disclosure includes knocking-out: swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, andknocking-in: HLA-C, HLA-E, HLA-G, HLA-F, and DQ.

In some embodiments, such non-transgenic engineered swine have fewerthan 10 genetic manipulations, such as no more than about 8, or no morethan about 5 genetic manipulations. In some embodiments, the engineeredswine include fewer than 20 such genetic manipulations, or in someembodiments, no more than about 15 or no more than about 10 geneticmanipulations.

Considering xenotransplantation in a parallel lens with the interactionsbetween maternal immune cells and fetal trophoblast cells of theplacenta during pregnancy, the mechanisms that permit maternal-fetaltolerance are translated and modified by the present inventors toprepare the hypoimmunogenic xenotransplantation product of the presentdisclosure. By genetically reprogramming SLA genes as described herein,knocking out one or more surface glycans, and optionally introducing alimited subset of apoptosis-inducing proteins and complement regulatoryproteins, the xenotransplantation product mimics the permitmaternal-fetal tolerance dynamic of fetal trophoblast cells duringpregnancy.

In certain aspects, the present disclosure centralizes (predicates) thecreation of hypoimmunogenic and/or tolerogenic cells, tissues, andorgans that does not necessitate the transplant recipients' prevalentand deleterious use of exogenous immunosuppressive drugs (or prolongedimmunosuppressive regimens) following the transplant procedure toprolong the life-saving graft. Instead, the central theorem of thisapproach is countervailing to the existing and previous dogmaticapproaches; instead, of accepting that innate and immovable disparitybetween donor and recipient, and thus focusing on interventions, genealterations, and/or concomitant exogenous immunosuppressive medicationsused as a method of reducing/eliminating/negatively-altering therecipients' naturally resulting immunologic response, we intentionallychoose to reverse the focus of the otherwise area of fundamentalscientific dogma. Rather than accept the immunological incompatibilitiesbetween the donor and recipient, specifically (but not limited to) thosemismatches of the Major Histocompatibility Complex(es), we intend toalter these catalytic antigens at the source, thereby eliminating all ofthe precipitating mechanisms that are the causative effectors of cell,tissue, and organ rejection between donor and recipient.

Thereby eliminating the rate-limiting step which requires burdensomelevels of immunosuppressive drugs/regimens, we indirectly (butsubstantially) address one of the central hindrances of the entire fieldof xenotransplantation. Namely, since 1996 (Patience, et al, 1997)concern regarding the infectious capacity of an otherwise (innocuous)endogenous retrovirus (PERV), ubiquitously expressed in all porcinecells, significantly limited the advancement of the present field ofscience. Moreover, refractory compromise or intentional suppression ofthe natural immunological capacity of the recipient—primarily viarequisite drugs to permit long-term organ/graft survival—furtherexacerbated concern regarding the potential clinical risk ofxenotransplantation therapeutics. Since, in the prevailing two decadesextensive research in has largely dispelled the concern regarding PERV;in tandem, efforts to eradicate all PERV(s) from the genome of potentialswine source donors. Our approach, which eliminates by the mechanism ofaddressing (and significantly reduces) the underlying, fundamental causeof organ-rejection phenomena, the existence and/or presence of PERV RNAdo not pose a credible risk to patients.

Restated, the former/previous approach to this unmet clinical need hasprecisely followed the classic medical dogma of “one-size fits all”.Instead, we vigorously thwart this limited view and pragmaticallydemonstrate the ability to harness present technological advances andfundamental principles to achieve a “patient-specific” solution whichdramatically improves clinical outcome measures. The former, we refer asthe “downstream” approach—which must contend with addressing all of thenatural immune processes in sequence. The latter, our approach, weoptimistically term the “upstream” approach—one which represents theculmination of unfilled scientific effort into a coordinatedtranslational effort.

Modification Techniques

It will be further understood that disruptions and modifications to thegenomes of source animals provided herein can be performed by severalmethods including, but not limited to, through the use of clusteredregularly interspaced short palindromic repeats (“CRISPR”), which can beutilized to create animals having specifically tailored genomes. See,e.g., Niu et al., “Inactivation of porcine endogenous retrovirus in pigsusing CRISPR-Cas-9,” Science 357:1303-1307 (22 Sep. 2017). Such genomemodification can include, but not be limited to, disrupted or eliminatedexpression of α-(1,3) galactosyl epitopes, any of the genetic ortransgenic modifications disclosed herein (e.g., as disclosed inDenner), and/or any other tailored genome modifications designed toreduce the bioburden and immunogenicity of products derived from suchsource animals to minimize immunological rejection.

Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein (Cas), originally known as amicrobial adaptive immune system, has been adapted for mammalian geneediting recently. The CRISPR/Cas system is based on an adaptive immunemechanism in bacteria and archaea to defend the invasion of foreigngenetic elements through DNA or RNA interference. Through mammaliancodon optimization, CRISPR/Cas has been adapted for precise DNA/RNAtargeting and is highly efficient in mammalian cells and embryos. Themost commonly used and intensively characterized CRISPR/Cas system forgenome editing is the type II CRISPR system from Streptococcus pyogenes;this system uses a combination of Cas9 nuclease and a short guide RNA(gRNA) to target specific DNA sequences for cleavage. A 20-nucleotidegRNA complementary to the target DNA that lies immediately 5′ of a PAMsequence (e.g., NGG) directs Cas9 to the target DNA and mediatescleavage of double-stranded DNA to form a DSB. Thus, CRISPR/Cas9 canachieve gene targeting in any N20-NGG site.

In some aspects, genome modification protein can be selected from aRNA-guided clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated (Cas) (CRISPR/Cas) nuclease system, aCRISPR/Cas dual nickase system, a zinc finger nuclease (ZFN), atranscription activator-like effector nuclease (TALEN), a meganuclease,a fusion protein comprising a programmable DNA binding domain linked toa nuclease domain (i.e., generates a double-stranded DNA break), andcombinations thereof. With the use of such genome modificationtechniques, a high rate of double-stranded breaks (DSB) for a high rateof modification either in somatic cells or in embryos is obtained and alarge number of genetically modified pigs are generated, e.g., throughsomatic cell nuclear transfer (SCNT) of modified somatic cells or directmicroinjection of engineered nucleases into the embryos. Somatic cellnuclear transfer or cloning involves screening of somatic cells(typically fetal fibroblasts), which carry the intended geneticalterations, and the nuclear transfer of the modified cells in a cloningprocess. Engineered nuclease can be easily applied to create eitherNHEJ- or HDR-induced mutations within a donor cell in vitro through apre-screening or selection strategy, which enables enrichment of cellscarrying the desired mutation. An alternative to SCNT is the methodinvolving direct gene editing in single-cell embryos. The mRNA ofeditors (for knockout) or together with donor DNA (for knock-in) can bemicroinjected into the cytoplasm or pronucleus of zygotes, which arethen transferred into the synchronized surrogates to generate editedanimals. This procedure is vastly simple compared with SCNT.

In other aspects, a fusion protein comprising a programmable DNA bindingdomain linked to a non-nuclease modification domain may be used formodifying genetic material. In certain aspects, the programmable DNAbinding domain of the fusion protein can be catalytically inactiveCRISPR/Cas system, a catalytically inactive meganuclease, a zinc fingerprotein, or a transcription activator-like effector, and thenon-nuclease modification domain of the fusion protein can haveacetyltransferase activity, deacetylase activity, methyltransferaseactivity, demethylase activity, kinase activity, phosphatase activity,ubiquitin ligase activity, deubiquitinating activity, adenylationactivity, deadenylation activity, SUMOylating activity, deSUMOylatingactivity, ribosylation activity, deribosylation activity, myristoylationactivity, demyristoylation activity, citrullination activity, helicaseactivity, amination activity, deamination activity, alkylation activity,dealkylation activity, oxidation activity, transcriptional activationactivity, or transcriptional repressor activity. In specific aspects,the non-nuclease modification domain of the fusion protein has cytosinedeaminase activity, histone acetyltransferase activity, transcriptionalactivation activity, or transcriptional repressor activity.

The methods may involve introducing into a eukaryotic cell (a) aprogrammable DNA modification protein or nucleic acid encoding theprogrammable DNA modification protein and (b) at least one programmableDNA binding protein or nucleic acid encoding the at least oneprogrammable DNA binding protein. The programmable DNA modificationprotein is targeted to a target chromosomal sequence and each of the atleast one programmable DNA binding proteins is targeted to a siteproximal to the target chromosomal sequence. Binding of the at least oneprogrammable DNA binding protein to the site proximal to the targetchromosomal sequence increases accessibility of the programmable DNAmodification protein to the target chromosomal sequence, therebyincreasing targeted genome modification efficiency and/or specificity.

Transgenic Approaches

In other aspects, swine source animals include transgenic animalsmodified to express human traits. Such additional modifications aredisclosed in, for example, in Denner J, “Xenotransplantation-Progressand Problems: A Review,” J Transplant Technol Res 4(2):133 (2014)(“Denner”), the entire disclosure of which is incorporated herein byreference. Such modifications may include, but are not limited to,hCD46-human membrane cofactor protein, MCP; hCD55-humandecay-accelerating factor, DAF; hCD59-human protectin; H-transferase,competing for the substrates needed by thealpha-1,3-galactosyltransferase; hCTLA4-Ig-human cytotoxic T-murinelymphocyte antigen 4 fused with Ig heavy chains, as a surrogate ligandused to block CD28/CTLA4 T-cell costimulation; hTM-human thrombomodulin,anticoagulation, activates protein C; hA20-tumor necrosisfactor-alpha-(TNF-alpha)-inducible gene, may control the AVR;HLA-E/beta-microglobulin-protection against human natural killer cellcytotoxicity; TRAIL-tumor necrosis factor related apoptosis inducingligand, induces apoptosis; hHO-1, human heme oxygenase-1,anti-apoptotic, cell protective, Fas-L-Fas ligand, belongs to the tumornecrosis factor (TNF) family, its binding with its receptor inducesapoptosis; GnT-III-β-1,4-N acetylglucosaminyltransferase III, catalyzesthe formation of a bisecting GlcNAc structure in N-glycans; shRNAPERV-PERV-specific short hairpin RNA, inhibits PERV expression by RNAinterference and other modifications. Such modifications may alsoinclude those set out in the following Table 1, reproduced from Denneras follows.

TABLE 1 Gene Effect 1,3 Gal (alpha-1,3- Reduced Galalpha-1,3-Gal (Gal)expression, galactosyltransferase) knock out reduced hyperacuterejection (GalTKO) hCD46 (hMCP, human membrane Human complementregulation cofactor) hCD46 + GalTKO Human complement regulation +Reduced Gal expression hCD55 (hDAF, human decay Human complementregulation accelerating factor) hCD55 + endo-beta- galactosidase C Humancomplement regulation + Reduced Gal expression hCD59 Human complementregulation hCD55 + hCD59 Human complement regulation hCD46 + hCD55 +hCD59 Human complement regulation H-transferase (alpha-1,2- Reduced Galexpression fucosyltransferase) hCD59 + H-transferase (alpha-1,2- Humancomplement regulation + fucosyltransferase) reduced Gal expressionhCTLA4-Ig (cytotoxic T lymphocyte- Inhibits T-cell activity associatedantigen) hTM (human thrombomodulin) Activate human anticoagulant proteinC hA20 (humanA20, tumor necrosis factor- Controls acute vascularrejection alpha inducible gene) HLA-E/(human leukocyte antigen-Protection from NK cell- mediated E) + human beta2- macroglobulincytotoxicity TRAIL (tumor necrosis factor-alpha- Reduced posthyperacutecellular rejection related apoptosis-inducing ligand) GnT-III(beta-d-mannoside beta-1,4-N- Reduced antigenicity to human naturalacetylglucosaminyltransferase III) antibodies hHO-1 (human hemeoxygenase-1) Antiapoptosis Fas ligand (Fas L) Antiapoptosis GalTKO +CD55 + CD59 Control of instant blood- mediated inflammatory reaction(IBMIR) when transplanting neonatal isle T- cell clusters GalTKO +CD55 + CD59 + H- Reduced xenoantibody response to isle T- Transferasecells from transgenic animals GalTKO + H-transferase Reduced expressionof alpha Gal antigen Soluble TNFRI-Fc-hHO Protection against oxidativeand inflammatory injury Optimized hTM Overcome coagulationincompatibilities in pig-to- primate xenotransplantation. GalTKO + CD46Suppress in vitro human anti- pig cellular responses HLA-E Suppressionof inflammatory macrophage- mediated cytotoxicity and proinflammatorycytokine production CD55 CD59 + H-transferase genes Enhanced protectiveresponse to human serum-mediated cytolysis

In some embodiments, such transgenic engineered swine have fewer than 10genetic manipulations, such as no more than about 8, or no more thanabout 5 genetic manipulations. In some embodiments, the engineered swineinclude fewer than 20 such genetic manipulations, or in someembodiments, no more than about 15 or no more than about 10 geneticmanipulations.

It is therefore understood that multiple source animals, with an arrayof biological properties including, but not limited to, genomemodification and/or other genetically engineered properties, can beutilized to reduce immunogenicity and/or immunological rejection (e.g.,acute, hyperacute, and chronic rejections) in humans resulting fromxenotransplantation. In certain aspects, the present disclosure can beused to reduce or avoid thrombotic microangiopathy by transplanting thebiological product of the present disclosure into a human patient. Incertain aspects, the present disclosure can be used to reduce or avoidglomerulopathy by transplanting the biological product of the presentdisclosure into a human patient. It will be further understood that thelisting of source animals set forth herein is not limiting, and thepresent invention encompasses any other type of source animal with oneor more modifications (genetic or otherwise) that serve(s) to reduceimmunogenicity and/or immunological rejection, singularly or incombination.

Single Knockout Swine that Includes PERV

It will be further understood that in some aspects, swine whose genomeslack or do not express active α-(1,3) galactosyl epitopes, whose genomesincludes PERV A, B, and C, and are produced by the processes describedherein, yield superior biological products derived from such sourceanimals to reduce immunogenicity in humans following xenotransplantationenhancing increased transplant longevity. Such production aspectsinclude, but are not limited to, the products being derived fromdesignated pathogen free animals maintained and propagated in designatedpathogen free facilities (including, but not limited to, facilities asdescribed herein); the animals and resulting products being free ofcertain pathogens including, but not limited to, Ascaris species,cryptosporidium species, Echinococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, porcine reproductive and respiratory syndrome,pseudorabies, staphylococcus species, Microphyton species, Trichophytonspecies, porcine influenza, porcine cytomegalovirus, arterivirus,coronavirus, Bordetella bronchiseptica, and Livestock-associatedmethicillin-resistant Staphylococcus aureus; the products beingminimally manipulated from the time of harvest to xenotransplantation;the products being live cell (e.g., vital, biologically active); theproducts being able to induce vascularization in a subject followingxenotransplantation; and/or the transplantation of the products notrequiring concomitant immunosuppressant drugs and/or otherimmunosuppressant therapies.

Such reduced immunogenicity of the products described herein issupported by at least two studies (set forth in Example 1 herein) whichshow skin grafts derived from swine whose genome lacks one or moreextracellular surface glycans including active α-(1,3) galactosylepitopes that were produced and prepared in accordance with the presentinvention performed significantly better on monkeys than prior studiesutilizing swine whose genome lacks active α-(1,3) galactosyl epitopes onmonkeys not produced and/or prepared in accordance with the presentinvention. See, e.g., Albritton et al., Lack of Cross-SensitizationBetween alpha-1, 3-Galactosyltransferase Knockout Porcine and AllogeneicSkin Grafts Permits Serial Grafting, Transplantation & Volume 97, Number12, Jun. 27, 2014, (Gal-T-KO skin grafts on recipient baboons fullyrejected by 12 or 13 days); Barone et al., Genetically modified porcinesplit-thickness skin grafts as an alternative to allograft for provisionof temporary wound coverage: preliminary characterization, Burns 41(2015) 565-574 (Gal-T-KO skin grafts on recipient baboons fully rejectedby 11 days); and Weiner et al., Prolonged survival of Gal-T-KO swineskin on baboons, Xenotransplantation, 2010, 17(2): 147-152 (Gal-T-KOxenogeneic split-thickness skin grafts on baboons fully rejected by 11days). Moreover, surprisingly, at least one study shows skin graftsderived from a DPF Closed Colony, α-1,3-galactosyltransferase [Gal-T]knockout pigs produced in accordance with the present inventionperformed better than allograft. See Example 1 herein. While the workingexamples herein demonstrate the advantageous results of the presentdisclosure using skin as a model organ, persons skilled in the art haverecognized that the same factors that result in successful skinxenotransplantation product correlate to success withxenotransplantation of other organs. Accordingly, the ability toxenotransplant various types of cells, tissues, and different organs isrecognized by persons of skill in the art where harvestedxenotransplantation tissue is shown to be resistant to rejection by therecipient's body for some period of time. These factors include theproduct of the present invention being viable, biologically active,non-terminally sterilized, having low immunogenicity, having lowbioburden, having low pathogenicity, inducing vascularization, collagengrowth, and/or other interactions from the transplant recipient inducingorgan or tissue adherence, organic union, or other temporary orpermanent acceptance by the recipient. As used herein, the phrase“terminally sterilized” refers to a product that has been sterilized inits final container and the phrase “non-terminally sterilized” refers toa product that has not been sterilized in its final container. Terminalsterilization typically involves filling and sealing product containersunder high-quality environmental conditions. Products are filled andsealed in this type of environment to minimize the microbial andparticulate content of the in-process product and to help ensure thatthe subsequent sterilization process is successful. The product in itsfinal container is then subjected to a sterilization process such asheat or irradiation. In contrast to a terminal sterilization process, inan aseptic process, the drug product, container, and closure are firstsubjected to sterilization methods separately, as appropriate, and thenbrought together. Due to their nature, certain products are asepticallyprocessed at an earlier stage in the process, or in their entirety.Because there is no process to sterilize the product in its finalcontainer, it is containers are filled and sealed in a high sterilityenvironment. Aseptic processing involves more variables than terminalsterilization. Before aseptic assembly into a final product, theindividual parts of the final product are generally subjected to varioussterilization processes. For example, glass containers may be subjectedto dry heat; containers may be subjected to UV irradiation and/oranti-pathogen baths; rubber closures may be subjected to moist heat; andliquids may be subjected to filtration. Each of these manufacturingprocesses requires validation and control. Each process could introducean error that ultimately could lead to the distribution of acontaminated product.

Closed Colonies General Closed Colony

Referring now to FIG. 1, in one aspect, animals are secured from theoutside to consider as candidates to add to the General Closed Colony128 that is housed within the SAF 100 to help propagate the DPF ClosedColony 102 also housed within the SAF 100 in a separate isolation area152. Transportation of the animals secured from the outside to the SAFis controlled to mitigate exposure to potential infectious agents. Suchmitigation techniques include, but are not limited to, using asterilized HEPA filtered cage during transport using a van cleaned withchlorhexidine and containing no other animals.

Candidate animals are initially quarantined to check health status andsuitability for intake into the General Closed Colony 128. For example,in some aspects, animals coming from the outside are first housed in aquarantine intake area 130 within the SAF and accompanied by a completehealth record (including, but not limited to, date of birth,vaccinations, infections, and antibiotic history), pedigree, and resultsof genetic tests. These animals reside in the quarantine intake area 130for at least seven (7) days as the accompanying records are evaluatedand other health screening measures are taken, including screening forsome infectious agents.

In some aspects, animals with poor health, questionable medical status,or are not able to be treated for such medical issues, will not beaccepted into the General Closed Colony 128 and/or will otherwise beculled from the quarantine area 130. Examples of acceptance criteriainclude, but are not limited to: (a) source animals are not born withany congenital defect that was unanticipated from the herd and thatcould have impacted the quality of health of the animal; (b) sourceanimals have received all vaccinations according to age and thevaccinations were killed agents; (c) any infections that occurred in thesource animal's lifetime have been reviewed as well as the clinicalintervention, and it was determined that the infection and any treatment(if applicable) did not impact the quality of the health of the animal;(d) results of the surveillance testing has been reviewed and it hasbeen verified that the source animal has been tested within the last 3months (with all source animals tested at sacrifice and all tests mustbe negative); (e) if the animal was injured in any way which requiredmedical attention, a review has been conducted and it has been confirmedthat the impact of the injury and the medical intervention (ifapplicable) had no impact on the health of the animal; and/or (f) PERVtests have been performed and results recorded.

In some aspects, animals that pass this screening process and timetableare moved out of the quarantine intake area 130 and into a generalholding area 132 within the SAF 100 to join or create an existing ornewly formed General Closed Colony 128. It will be understood that thegeneral holding area 132 is kept under closed colony conditionssubstantially similar to the conditions applied to the DPF Closed Colony102 in the DPF Isolation Area 152.

It will be further understood that, excluding their offspring, candidateanimals secured from the outside will never become members of the DPFClosed Colony. Piglets from the General Closed Colony 128 animals willbe utilized to create and/or propagate the DPF Closed Colony as furtherdescribed herein.

DPF Closed Colony Pregnant Sows and DPF Piglets

In one aspect, pregnant sows 134 (or gilts) are obtained from theoutside or from the General Closed Colony 128 to produce piglets tocreate and/or add to the DPF Closed Colony 102 herd. For example, in oneaspect, sows 134 are placed in a sow quarantine area 136 within the SAFuntil the time to give birth, in this aspect via Cesarean section inorder to avoid exposing the piglet to potential pathogens, includingPorcine Cytomegalovirus (pCMV). Contraction of pCMV in piglets can occurwhen the piglets travel through the vagina of the sow during naturalbirth. The piglets, by virtue of their birthing through Cesarean sectionas described herein, prevents such contraction and the piglets producedthrough the methods described herein are pCMV-free.

Prior to the Cesarean section procedure, for example the morning of theprocedure, an operating room 138 within the SAF 100 prepared accordingto standard operating room protocols in a sterile environment with 2sides: Side A 140 for the Cesarean section of the sow, and Side B 142 toreceive the piglets 144 that are candidates to either found or add tothe DPF Closed Colony.

The sow 134 is brought into the operating room 138 for captive bolteuthanasia. Immediately following this, the sow 134 is placed in theleft lateral decubitus position and the abdomen and torso are preppedwidely with chlorhexidine and draped in a sterile fashion. A flankincision is expeditiously made and the abdominal muscles are split inorder to gain access into the peritoneum. The uterus is exteriorized,incised and the piglets 144 are removed after doubly clamping anddividing the umbilical cord. Immediate execution of the surgicalprocedures following captive bolt euthanasia is critical to the survivalof the piglets 144.

Infection controls for the piglets 144 are implemented at birth. Thepiglets 144 are placed in a warmed 1% chlorhexidine (or othersterilization agent, such as betadine) in sterile saline bath solutionand then passed over to piglet handlers to a resuscitation area 148 forresuscitation, rewarming and gavage feeding of the first dose ofcolostrum. The sow's 134 carcass is closed by staff with suture anddisposed of following appropriate procedures.

The piglets 144 are subsequently quarantined in a separate sterilepiglet quarantine room 150 then transferred to a designated pathogenfree isolation area (“DPF Isolation Area”) 152 to either create or jointhe DPF Closed Colony 102. It will be understood that the DPF IsolationArea 152 can be of any size suitable to manage and maintain the DPFClosed Colony to the extent needed for breeding, rearing, birthing,harvesting, and overall management as described herein.

In one aspect, the DPF Isolation Area 152 that supports the DPF ClosedColony is a restricted access, positive-pressure barrier isolationsuite, approximately 500 ft², with an animal husbandry capacity tosupport at least 9 animals (up to 20 kg each), inside the larger SAF100. It will be understood that the DPF Isolation Area 152 can besignificantly larger than this, and can include multiple areas(including, but not limited to, multiple rooms and suites), depending onthe need of the number of source animals and demand for products, inaccordance with the products and methods as described herein.

In some aspects, tracking of piglets is performed and piglets arehandled under designated pathogen free conditions in the DPF IsolationArea 152. For example, handling of piglets is performed wearing personalprotective equipment (“PPE”) in the DPF Isolation Area 152, includingface mask, gloves, shoe covers, and hair bonnet. The animals are handledby clean personnel, personnel who have not entered any animal room orfacility where other swine are housed. For tracking, piglets are earnotched 3 days after birth and ear tagged with hand-labeled plastic eartags at weaning (usually 3-5 weeks).

It will be understood that some piglets are raised in the DPF ClosedColony 102 in the DPF Isolation Area 152 as a source forxenotransplantation products, and some piglets in the DPF Closed Colony102 are allowed to mature and be used to propagate the General ClosedColony 128. In the event of propagation of the General Closed Colony128, the matured animal is removed from the DPF Isolation Area 152 andadded to the General Closed Colony 128 for breeding. Since the DPFIsolation Area 152 is controlled to be DPF, once these or any otheranimals leave DPF Isolation Area 152, those animals never return to theDPF Isolation Area 152.

Precautions are taken to prevent the exposure of any animals within theDPF Closed Colony 102 to contamination (for example, blood, bloodproducts or tissues obtained from animals outside the DPF Closed Colony102). If any animals within the DPF Closed Colony 102 are inadvertentlyexposed to blood, blood products, or tissues obtained from animalsoutside the DPF Closed Colony 102, those animals are removed from theDPF Closed Colony 102 and will never return to the DPF Closed Colony102. Aseptic techniques and sterile equipment for all parenteralinterventions are used, and routine procedures such as vaccinations,treatment with drugs or biologics, phlebotomy, and biopsies areperformed. The DPF Isolation Area 152 is restricted by card access onlyto specially authorized and trained staff.

In another aspect of the invention, in some aspects, newborn piglets arehandled and hand-reared by trained and gowned staff in the DPF IsolationArea 152 to ensure their health and that they are maintained asdesignated pathogen free.

Propagation

The DPF Closed Colony 102 can be propagated in multiple ways. Forexample, as described herein, sows 134 may be taken from the outside orGeneral Closed Colony 128, quarantined, and have their piglets 144delivered via Cesarean section, with the piglets resuscitated,sterilized, quarantined, and placed into the DPF Isolation Area 152.Newborn piglets may be maintained at 26-30° C. or 80-85° F. In someaspects, heat lamps are used to keep animals warm. Newborn piglets areinitially housed in sterilized medium crates in the SAF with steriletowels/drapes on the bottom.

The DPF Closed Colony 102 may also be propagated in other ways. Forexample, in one aspect, the DPF Closed Colony 102 is propagated throughnatural intercourse amongst the animals in the DPF Closed Colony 102occurring entirely within the DPF Isolation Area 152. It will beunderstood that pregnancies may also occur in the DPF Closed Colony 102within the DPF Isolation Area 152 as a result of artificial inseminationor other breeding techniques that do not involve natural intercourse.

In such aspects, pregnant sows 154 (or gilts) in the DPF Closed Colony102 within the DPF Isolation Area 152 carry the entire pregnancy andpiglets are delivered through live vaginal birth and Caesarian sectionis not necessary. Importantly, the piglets resulting from naturalintercourse and live vaginal birth within the DPF Isolation Area 152 aredesignated pathogen free, including no infection by pCMV.

Following the live vaginal birth, piglets are immediately taken awayfrom the sow to prevent the sows from harming the piglets. The pigletsare then hand-reared from birth by humans within the DPF Isolation Area152 in the methods as described herein.

In the case of mating in the DPF Closed Colony 102 or General ClosedColony 128, the breeding of swine disclosed herein is typicallyhomozygous to homozygous breeding. Females are given hormones two weeksbefore gestation then throughout pregnancy. Furthermore, as with the DPFClosed Colony 102, the General Closed Colony 128 may also be propagatedthrough natural intercourse amongst the animals in the General ClosedColony 128, and may also occur as a result of artificial insemination orother assisted reproductive technologies (ARTs) that do not involvenatural intercourse.

Various techniques have been developed and refined to obtain a largenumber of offspring from genetically superior animals or obtainoffspring from infertile (or subfertile) animals. These techniquesinclude: artificial insemination, cryopreservation (freezing) of gametesor embryos, induction of multiple ovulations, embryo transfer, in vitrofertilization, sex determination of sperm or embryos, nuclear transfer,cloning, etc.

Artificial insemination (AI) has been used to obtain offspring fromgenetically superior males for more than 200 years. Improvements inmethods to cryopreserve (freeze) and store semen have made AI accessibleto more livestock producers. In the same manner as cryopreservation ofsemen, embryo freezing allowed for the global commercialization ofanimals with high genetic qualities.

Multiple ovulation and embryo transfer: Development of embryo transfertechnology allows producers to obtain multiple progeny from geneticallysuperior females. Depending on the species, fertilized embryos can berecovered from females (also called embryo donors) of superior geneticmerit by surgical or nonsurgical techniques. The genetically superiorembryos are then transferred to females (also called embryo recipients)of lesser genetic merit. In cattle and horses, efficient techniquesrecover fertilized embryos without surgery, but only one or sometimestwo embryos are produced during each normal reproductive cycle. In swineand sheep, embryos must be recovered by surgical techniques. To increasethe number of embryos that can be recovered from genetically superiorfemales, the embryo donor is treated with a hormone regimen to inducemultiple ovulations, or superovulation.

In vitro Fertilization: As an alternative to collecting embryos fromdonor animals, methods have been developed recently to produce embryosin vitro (in the laboratory). The methods are also called in vitroembryo production. Immature oocytes (female eggs) can be obtained fromovaries of infertile or aged females, or from regular embryo donors(described above). Ovum (egg) pick up is a nonsurgical technique thatuses ultrasound and a guided needle to aspirate immature oocytes fromthe ovaries. Once the immature oocytes have been removed from the ovary,they are matured, fertilized, and cultured in vitro for up to seven daysuntil they develop to a stage that is suitable for transfer or freezing.

Since the mid 1980s, technology has been developed to transfer thenucleus from either a blastomere (cells from early, and presumablyundifferentiated cleavage stage embryos) or a somatic cell (fibroblast,skin, heart, nerve, or other body cell) to an enucleated oocyte(unfertilized female egg cell with the nucleus removed). This “nucleartransfer” produces multiple copies of animals that are themselves nearlyidentical copies of other animals (transgenic animals, geneticallysuperior animals, or animals that produce high quantities of milk orhave some other desirable trait, etc.). This process is also referred toas cloning. To date, somatic cell nuclear transfer has been used toclone cattle, sheep, pigs, goats, horses, mules, cats, rabbits, rats,and mice.

The technique involves culturing somatic cells from an appropriatetissue (fibroblasts) from the animal to be cloned. Nuclei from thecultured somatic cells are then microinjected into an enucleated oocyteobtained from another individual of the same or a closely relatedspecies. Through a process that is not yet understood, the nucleus fromthe somatic cell is reprogrammed to a pattern of gene expressionsuitable for directing normal development of the embryo. After furtherculture and development in vitro, the embryos are transferred to arecipient female and ultimately result in the birth of live offspring.The success rate for propagating animals by nuclear transfer is oftenless than 10 percent and depends on many factors, including the species,source of the recipient ova, cell type of the donor nuclei, treatment ofdonor cells prior to nuclear transfer, the techniques used for nucleartransfer, etc.

Most commonly used ARTs rely on fertilization as a first step. Thisjoining of egg and sperm is accompanied by the recombination of thegenetic material from the sire and dam, and is often referred to as“shuffling the genetic deck.” It will be understood that these breedingtechniques can be used either within the DPF Closed Colony, as abreeding step within the DPF Isolation Area 152, or could be used as abreeding step for females in the General Closed Colony and/or from theoutside.

In the case of utilization of ART to impregnate females in the GeneralClosed Colony, and/or a female from the outside, the birthing of pigletsfrom such females can be as described herein, i.e., sows 134 may betaken from the outside or General Closed Colony 128, quarantined, andhave their piglets 144 delivered via Cesarean section, with the pigletsresuscitated, sterilized, quarantined, and placed into the DPF IsolationArea 152.

Maintenance of Closed Colonies

It will be understood that the phrase “designated pathogen free,” asused herein, can be used to describe animals, animal herds, animalproducts derived therefrom, and/or animal facilities that are free ofone or more specified pathogens. Preferably, such “designated pathogenfree” animals, animal herds, animal products derived therefrom, and/oranimal facilities are maintained using well-defined routines of testingfor such designated pathogens, utilizing proper standard operatingprocedures (SOPs) and practices of herd husbandry and veterinary care toassure the absence and/or destruction of such designated pathogens,including, but not limited to, routines, testing, procedures, husbandry,and veterinary care disclosed and described herein. It will be furtherunderstood that as used herein the terms “free,” “substantially free”and like terms when used in connection with “pathogen free” are meant toindicate that the subject pathogens are not present, not alive, notactive, or otherwise not detectable by standard or other testing methodsfor the subject pathogens.

Designated pathogens may include any number of pathogens, including, butnot limited to, viruses, bacteria, fungi, protozoa, parasites, and/orprions (and/or other pathogens associated with transmissible spongiformencephalopathies (TSEs)). Designated pathogens could include, but not belimited to, any and all zoonotic viruses and viruses from the followingfamilies: adenoviridae, anelloviridae, astroviridae, calicivirdae,circoviridae, coronaviridae, parvoviridae, picornaviridae, andreoviridae.

Designated pathogens could also include, but not be limited to,adenovirus, arbovirus, arterivirus, bovine viral diarrhea virus,calicivirus, cardiovirus, circovirus 2, circovirus 1, coronavirus,encephalomyocarditus virus, eperytherozoon, Haemophilus suis, herpes andherpes-related viruses, iridovirus, kobuvirus, leptospirillum, Listeria,Mycobacterium TB, mycoplasma, orthomyxovirus, papovirus, parainfluenzavirus 3, paramyxovirus, parvovirus, pasavirus-1, pestivirus,picobirnavirus (PBV), picornavirus, porcine circovirus-like(po-circo-like) virus, porcine astrovirus, porcine bacovirus, porcinebocavirus-2, porcine bocavirus-4, porcine enterovirus-9, porcineepidemic diarrhea virus (PEDV), porcine polio virus, porcinelymphotropic herpes virus (PLHV), porcine stool associated circularvirus (PoSCV), posavirus-1, pox virus, rabies-related viruses, reovirus,rhabdovirus, Rickettsia, sapelovirus, sapovirus, Staphylococcus hyicus,Staphylococcus intermedius, Staphylococcus epidermidis,coagulase-negative staphylococci, suipoxvirus, swine influenza, teschen,torovirus, torque teno sus virus-2 (TTSuV-2), transmissiblegastroenteritus virus, vesicular stomatitis virus, and/or any and/or allother viruses, bacteria, fungi, protozoa, parasites, and/or prions(and/or other pathogens associated with TSEs). In some aspects,particularly in swine herds, testing for TSEs is not performed becauseTSEs are not reported in natural conditions in swine. In other aspects,testing for TSEs is performed as part of the methods of the presentdisclosure.

There are huge numbers of pathogens that could possibly be tested for inanimal herds, and there is no regulatory guidance or standard, orunderstanding in the field as to what specific group of pathogens shouldbe tested for in donor animals, and which specific group of pathogensshould be removed from donor animal populations in order to ensure safeand effective xenotransplantation. In other words, before the presentdisclosure, there was no finite number of identified, predictablepathogens to be tested for and excluded. The present disclosure providesa specific group of pathogens identified by the present inventors thatare critical to exclude for safe and effective xenotransplantation, asset forth in the following Table 2.

TABLE 2 Test Pathogen Parasite Fecal Float Ascaris speciesCryptosporidium species Echinococcus Strongyloids sterocolis Toxoplasmagondii Brucella BAPA (buffered Brucella suis acidified plateagglutination test) Lepto6 Screen Leptospira species M Hyo MycoplasmaHyopneumoniae PRRS x3 ELISA Porcine Reproductive and RespiratorySyndrome Virus (PRRSV) PRVgb Test Pseudorabies TGE/PRCV Test PorcineRespiratory Coronavirus Toxoplasmosis ELISA Toxoplasma Gondii PorcineCytomegalovirus Porcine CMV PCR Porcine Influenza PCR Porcine InfluenzaA Nasal swab Bordetella bronchiseptica Skin culture Coagulase-positivestaphylococci Skin culture Coagulase-negative staphylococci Skin cultureLivestock-associated methicillin resistant Staphylococcus aureus (LAMRSA) Skin culture Microphyton and Trichophyton spp. Porcine EndogenousPorcine Endogenous Retrovirus Retrovirus RT-PCR Assay (PERV) C (PERV C)

In certain aspects, a product of the present disclosure is sourced fromanimals having antibody titer levels below the level of detection for aplurality of or all of the pathogens discussed in the presentdisclosure. In certain aspects, subjects transplanted with a product ofthe present disclosure are tested and found to have antibody titerlevels below the level of detection for a plurality of or all of thepathogens discussed in the present disclosure.

In some aspects, the present disclosure includes a method of testing fora specific group of pathogens consisting of no more than 18-35, e.g.,35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, or18 pathogens, the specific group of pathogens including each of thepathogens identified in Table 2. In some aspects, the present disclosureincludes creating, maintaining and using donor animals that are free ofthe 18-35, e.g., 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22,21, 20, 19, or 18 pathogens, the specific group of pathogens includingeach of the pathogens identified in Table 2.

As described herein, piglets born via live vaginal birth within the DPFClosed Colony 102 are not infected with pCMV, but are nonetheless testedfor pCMV on a continuous basis. Testing for Porcine Cytomegalovirus(pCMV) and Porcine Endogenous Retrovirus (PERV), should be routine andcontinuous for screening and maintenance as described herein, and shouldoccur routinely and continuously for the DPF Closed Colony. In someaspects of the present invention, the source animals described hereinare positive for PERV A and B only, and some are positive for PERV A, B,and C. In other aspects, the source animals are free of PERV A, B and/orC (through utilization of CRISPR and other techniques).

With respect to PERV, it is understood that most, if not all, swine areknown to be positive for PERV A and B. While PERV is recognized, therisk of transmission of PERV from treatment with swine derived tissue isexpected to be rare. To date eight PERV mRNAs are expressed in allporcine tissues and in all breeds of swine and preclinical and clinicalxenotransplantation studies of humans exposed to pig cells, tissues, andorgans including pancreatic islets have failed to demonstratetransmission of PERV. See, e.g., Morozov V A, Wynyard S, Matsumoto S,Abalovich A, Denner J, Elliott R, “No PERV transmission during aclinical trial of pig islet cell transplantation,” Virus Res 2017;227:34-40. In the unlikely event that a human infection should occur,PERV is susceptible in vitro to nucleoside and non-nucleoside reversetranscriptase inhibitors in common clinical use. See, e.g., Wilhelm M,Fishman J A, Pontikis R, Aubertin A M, Wilhelm F X, “Susceptibility ofrecombinant porcine endogenous retrovirus reverse transcriptase tonucleoside and non-nucleoside inhibitors,” Cellular & Molecular LifeSciences 2002; 59:2184-90; Schuurman, H., “Regulatory aspects ofclinical xenotransplantation,” Int. J. Surg., 23, (2015), pp. 312-321.Experimental data using the xenotransplantation product of the presentdisclosure indicated that PERV genetic material was not detected in therecipient's organs and that porcine DNA and cells did not migrate intothe circulation of the recipient from the xenotransplanted organ.

The DPF Closed Colony 102 is maintained to ensure that the animalsremain designated pathogen free and that appropriate standards of animalcare and well-being are applied at all levels of the SAF 100 (i.e.,breeding, maintenance, propagation). For example, continuous testing forpathogens and other biological markers occurs including the numerouspathogens identified herein (including, but not limited to, pCMV andother pathogens). Environmental and blood samples are collected asnecessary for genotyping and testing for pathogens. Test result(s)obtained for pathogens or other health concerns are evaluated by thefacility veterinarian who may recommend follow-up testing andobservations, and quarantine of the facility or areas (e.g., rooms,suites or other areas) within a facility as needed. Carefuldocumentation of any antimicrobial agents used during routine care ofthe source animals should be maintained, and exclusive use of killedvaccines used. Examples of antimicrobial agents include cefazolin,bacitracin, neomycin, and polymyxin.

In some aspects, routine health surveillance and screening for pathogens(e.g., adventitious agents) of source animals is performed every 3months. Samples of serum, nasal swabs, and stool for each animal in theGeneral and DPF Closed Colonies are obtained and provided for analyticaltests for detection of such pathogens every 3 months. Source animalsamples of serum, nasal swabs, and stool for testing are obtainedimmediately after euthanasia via captive bolt and evaluated as disclosedherein including one or more of: conducting a sterility assay andconfirming that aerobic and anaerobic bacteria do not grow in thesterility assay; conducting a mycoplasma assay and confirming thatmycoplasma colonies do not grow in the mycoplasma assay; conducting anendotoxin assay and confirming that the biological product is free ofendotoxins in the endotoxin assay, conducting the MTT-reduction assayand confirming that the product has at least 50% cell viability in theMTT-reduction assay; conducting flow cytometry and confirming that theproduct does not have galactosyl-a-1,3-galactose epitopes as determinedby the flow cytometry; conducting pathogen-detection assays specific for18 to 35 pathogens and confirming that the product is free of Ascarisspecies, Cryptosporidium species, Echinococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, Mycoplasmahyopneumoniae, porcine reproductive and respiratory syndrome,pseudorabies, Staphylococcus species, Microphyton species, Trichophytonspecies, porcine influenza, porcine cytomegalovirus, arterivirus,coronavirus, Bordetella bronchiseptica, and Livestock-associatedmethicillin-resistant Staphylococcus aureus.

In some aspects, all swine undergo routine health monitoring, whichincludes documentation of all illnesses, medical care, procedures, drugsadministered, vaccinations, physical examinations, any treatmentsreceived, and general health assessments and observations each day attime of feeding with a visual health inspection indicating the animal isable to stand, move freely and appears clinically normal, as well asobservations relating to the animal's appearance, activity and appetite,recording on the Animal Husbandry Log any deficiencies. In some aspects,animals are vaccinated against Mycoplasma hyopneumoniae, HemophilusParasuis, Streptococcus suis, Pasteurella multocida, Bordatellabronchiseptica and Erysipelothrix rhusiopathiae. All swine six months orolder may be vaccinated against Erysipelothrix rhusiopathiae, Leptospira(Canicola-Grippotyphosa-Hardjo-Icterohaemorrhagiae-Pomona), Influenzaand Parvovirus. Repeat vaccination may be performed, e.g., every sixmonths.

In some aspects, health monitoring will normally be performed as part ofdaily husbandry procedures for cleaning and feeding to minimize entryinto swine holding areas (e.g., rooms, suites or other areas). Prior toentering, personnel must wear personal protective equipment (PPE) andensure that their footwear is free from gross contamination (e.g.visible dirt or mud). They will then don disposable shoe/boot coversprior to entry. Personnel in contact with any animals not housed in thedesignated pathogen free facility will change PPE if contaminated. Allimplements (shovel, other necessary tools) will undergo chlorhexidineimmersion of no less than 2 minutes if exogenous to vivarium and judgednecessary. Solid waste and soiled bedding is removed. Animal holdingareas are sanitized with diluted Quat-PV or bleach a minimum of onceevery two weeks.

In some aspects, bedding is replaced daily using irradiated bedding woodshavings. The replacement amount is an approximate equal amount to thatwhich was removed. All bedding is completely replaced on a weekly basisat a minimum. Daily activities including health status checks, cleaningand water levels are documented in the Animal Husbandry log.Appropriately labeled trash and biological waste is picked up by staffdaily and incinerated.

With regard to piglet, newborns are handled and cared for by trained andgowned staff in an isolation suite. All supplies, room and crates aresanitized prior to housing of the piglets. Sterile drapes and towels areused to line the bottom of the crates. Room temperature is controlled to80-85° F. Animals crates are maintained at 85-95° F. through the use ofheat lamps. Piglets are maintained in the crates through the first 2weeks after which time piglets are housed on the floor with irradiatedwood shavings. Crates are cleaned daily and shavings are removed andreplenished daily. Piglets are initially fed fresh-made, sterilecolostrum (Bovine Colostrum IgG formulated for swine, Sterling NursemateASAP or equivalent) using a feeding tube every 1 to 2 hours until pigletis self-feeding from feeder. During the early days, the piglet isweighed twice a day and well-being is checked and recorded twice a day.Starting at day 14, piglets are fed 3 times per day with a Milk Replacer(Ralco Birthright or equivalent) that is further supplemented withirradiated piglet grain (antibiotic free creep feed, Blue Seal 813 orequivalent). The amount each piglet eats at each feeding is recorded.Vaccinations, genotyping, ear notching, and needle teeth trimming areperformed within the first 7 days after birth of the piglet. In someaspects, vaccines use killed agents. Piglets are vaccinated againstMycoplasma hyopneumoniae, Hemophilus Parasuis, Streptococcus suis,Pasteurella multocida, Bordatella bronchiseptica and Erysipelothrixrhusiopathiae at Day 7 after Birth, with a Booster Vaccination at 28days of age. In one aspect, vaccines are killed agents. All swine sixmonths or older are vaccinated against Erysipelothrix rhusiopathiae,Leptospira (Canicola-Grippotyphosa-Hardjo-Icterohaemorrhagiae-Pomona),Influenza and Parvovirus. Repeat vaccination is performed every sixmonths.

The source animals for the xenotransplantation product are maintained ina positive pressure, biocontainment establishment, under specificisolation-barrier conditions governed by standard operation proceduresadopted by the managers of the given program, and receive specializedcare, under controlled conditions in order to mitigate adventitiousagents. To ensure the welfare of the closed colony of source animalsintended for xenotransplantation use, the SAF, personnel, and thecaretakers of source animals adhere to procedures for animal husbandry,tissue harvesting, and sacrifice of animals. The source animals arehoused in a positive pressure, biocontainment establishment, underspecific isolation-barrier conditions.

In some aspects, food and bedding are delivered to a loading dock,transported, and stored in a specific feed room off of the clean cagewash area accessible only to staff in the inner hallway. All bedding andfeed are sterilized by irradiation and double bagged to insuresterility. Feed used for the piglets and more mature animals is definedgrain feed by a specific manufacturer. It does not contain any cattleprotein. Water supply is provided either by use of the facility sterilesystem or purchased sterile water which is dispensed into sterile pans.Records for storage and delivery of feed, water, and other consumablesare maintained, and include manufacturer, batch numbers, and otherpertinent information, per protocol.

In some aspects, animal records are maintained to describe the feedprovided to source animals for at least two generations before their useas a source for live tissues, organs and/or cells used inxenotransplantation. This includes source, vendor, and the type of feedused (including its contents). Use of feed that has been derived fromanimals is prohibited. Source animals are not provided feeds containinganimal proteins or other cattle materials that are prohibited by the FDAfeed ban as expanded in 2008 as source animals (21 CFR 589.2000) orfeeds containing significant drug contamination or pesticide orherbicide residues for source animals (21 CFR 589.2001).

In some aspect, purified water is provided in sufficient quality toprevent unnecessary exposure of animals to infectious pathogens, drugs,pesticides, herbicides, and fertilizers. Newborn animals are providedcolostrum specifically qualified for herd qualification. In someaspects, Bovine Colostrum IgG formulated for swine, Sterling NursemateASAP or equivalent is used to feed newborn animals.

Biological Products Derived from DPF Closed Colony Biological Products

As described herein, biological products for xenotransplantation arederived from source animals produced and maintained in accordance withthe present invention, including from the DPF Closed Colony 102 asdescribed herein. Such biological products include, but are not limitedto, liver, kidney, skin, lung, heart, pancreas, intestine, nerve andother organs, cells and/or tissues.

Harvesting of such biological products occurs in a single, continuous,and self-contained, segregated manufacturing event that begins with thesacrifice of the source animal through completion of the production ofthe final product. The animal is euthanized via captive bolt euthanasia,may be moved, if necessary, in a sterile, non-porous bag, to anoperating room where the procedure to harvest biological product fromthe source animal will occur. All members of the operating team shouldbe in full sterile surgical gear, e.g., dressed in sterile dress tomaintain designated pathogen free conditions prior to receiving thesource animal and in some instanced be double-gloved to minimizecontamination, and surgical areas and tools are sterilized. The sourceanimal is removed from the bag and container in an aseptic fashion. Thesource animal is scrubbed by operating staff, e.g., for at least 1-10minutes with antiseptic, e.g., Chlorhexidine, brushes over the entirearea of the animal where the operation will occur, periodically pouringChlorhexidine over the area to ensure coverage. Surgical area(s) of theanimal are scrubbed with opened Betadine brushes and sterile water rinseover the entire area of the animal where the operation will occur for,e.g., 1-10 minutes. For surgery, operators will be dressed in steriledress in accordance with program and other standards to maintaindesignated pathogen free conditions. All organs, cells or tissue fromthe source animal that will be used for xenotransplantation is harvestedwithin 15 hours of the animal being sacrificed.

Biological products can also include, but are not limited to, thosedisclosed herein (e.g., in the specific examples), as well as any andall other tissues, organs, and/or purified or substantially pure cellsand cell lines harvested from the source animals. In some aspects,tissues that are utilized for xenotransplantation as described hereininclude, but are not limited to, areolar, blood, adenoid, bone, brownadipose, cancellous, cartaginous, cartilage, cavernous, chondroid,chromaffin, connective tissue, dartoic, elastic, epithelial, Epithelium,fatty, fibrohyaline, fibrous, Gamgee, Gelatinous, Granulation,gut-associated lymphoid, Haller's vascular, hard hemopoietic,indifferent, interstitial, investing, islet, lymphatic, lymphoid,mesenchymal, mesonephric, mucous connective, multilocular adipose,muscle, myeloid, nasion soft, nephrogenic, nerve, nodal, osseous,osteogenic, osteoid, periapical, reticular, retiform, rubber, skeletalmuscle, smooth muscle, and subcutaneous tissue. In some aspects, organsthat are utilized for xenotransplantation as described herein include,but are not limited to, skin, kidneys, liver, brain, adrenal glands,anus, bladder, blood, blood vessels, bones, cartilage, cornea, ears,esophagus, eye, glands, gums, hair, heart, hypothalamus, intestines,large intestine, ligaments, lips, lungs, lymph, lymph nodes and lymphvessels, mammary glands, mouth, nails, nose, ovaries, oviducts,pancreas, penis, pharynx, pituitary, pylorus, rectum, salivary glands,seminal vesicles, skeletal muscles, skin, small intestine, smoothmuscles, spinal cord, spleen, stomach, suprarenal capsule, teeth,tendons, testes, thymus gland, thyroid gland, tongue, tonsils, trachea,ureters, urethra, uterus, and vagina.

In some aspects, purified or substantially pure cells and cell linesthat are utilized for xenotransplantation as describe herein include,but are not limited to, blood cells, blood precursor cells, cardiacmuscle cells, chondrocytes, cumulus cells, endothelial cells, epidermalcells, epithelial cells, fibroblast cells, granulosa cells,hematopoietic cells, Islets of Langerhans cells, keratinocytes,lymphocytes (B and T), macrophages, melanocytes, monocytes, mononuclearcells, neural cells, other muscle cells, pancreatic alpha-1 cells,pancreatic alpha-2 cells, pancreatic beta cells, pancreatic insulinsecreting cells, adipocytes, epithelial cells, aortic endothelial cells,aortic smooth muscle cells, astrocytes, basophils, bone cells, boneprecursor cells, cardiac myocytes, chondrocytes, eosinophils,erythrocytes, fibroblasts, glial cells, hepatocytes, keratinocytes,Kupffer cells, liver stellate cells, lymphocytes, microvascularendothelial cells, monocytes, neuronal stem cells, neurons, neutrophils,pancreatic islet cells, parathyroid cells, parotid cells, platelets,primordial stem cells, Schwann cells, smooth muscle cells, thyroidcells, tumor cells, umbilical vein endothelial cells, adrenal cells,antigen presenting cells, B cells, bladder cells, cervical cells, conecells, egg cells, epithelial cells, germ cells, hair cells, heart cells,kidney cells, leydig cells, lutein cells, macrophages, memory cells,muscle cells, ovarian cells, pacemaker cells, peritubular cells,pituitary cells, plasma cells, prostate cells, red blood cells, retinalcells, rod cells, Sertoli cells, somatic cells, sperm cells, spleencells, T cells, testicular cells, uterine cells, vaginal epithelialcells, white blood cells, ciliated cells, columnar epithelial cells,dopaminergic cells, dopaminergic cells, embryonic stem cells,endometrial cells, fibroblasts fetal fibroblasts, follicle cells, gobletcells, keratinized epithelial cells, lung cells, mammary cells, mucouscells, non-keratinized epithelial cells, osteoblasts, osteoclasts,osteocytes, and squamous epithelial cells.

An organ is a group of related cells that combine together to performone or more specific functions within the body. Biologically, skin isthe body's largest and fastest-growing organ, and is classified as theprimary component of the integumentary system, one of the tenmacro-organ systems found in “advanced” animals. Skin fulfills severalcritical roles including regulating temperature, providing a dynamicbarrier to the external world, and serving as a conduit to support animmense network of sensory receptors. The skin performs severalfunctions that are vital to the survival and health of the body. Theskin heals to prevent the loss of blood after wounds, regulates bodytemperature by dissipating heat and as a layer against cold, absorption,secretion, thermal-regulation, sensory detection and orientation, andbarrier protection. In fact, not only has success in transplantation ofskin been recognized to correlate to transplantation of other organs,but skin transplants appear to be more sensitive to rejection than otherorgans, e.g., immune privileged organs such as liver, and skintransplants have even been suggested for use as “sentinel transplants,”i.e., use of skin grafts in a human recipient as early predictors ofrejection of transplanted solid organs in the same recipient. Forexample, as reported in Ali et al. Transplant Proc. 2016 October;48(8):2565-2570, evidence provided by experience with abdominal walltransplantation in some intestinal and multivisceral transplantrecipients suggest that rejection may manifest in the skin componentbefore emergence in the intestinal allograft, providing a “lead time”during which treatment of rejection of the abdominal wall could preventthe emergence of intestinal rejection.

Further, United States Code Title 42, Section 274 and Section 301,explicitly list skin in its formal definition of human organs, i.e.,“‘Human organ,’ as covered by section 301 of the National OrganTransplant Act, as amended, means the human (including fetal) kidney,liver, heart, lung, pancreas, bone marrow and other hematopoieticstem/progenitor cells without regard to the method of their collection,cornea, eye, bone skin, and intestine, including the esophagus, stomach,small and/or large intestine, or any portion of the gastrointestinaltract.” Similarly, the Human Organ Transplant Ordinance (HOTO), aninternationally ratified ordinance to prevent organ trading and protectdonor and recipient rights to self-determination. This globallegislation lists skin—and whole segments of the integumentarysystem—formally as an organ, and more broadly defines an organ as “anypart of the human body consisting of a structured arrangement of tissueswhich, if wholly removed, cannot be regenerated by the body . . . .”Following, the formal medical definition of a transplant is: “theremoval of tissue from one part of the body or from one individual andits implantation or insertion in another especially by surgery.” TheHOTO defines a transplant as “the transfer of an organ from one personto another during a transplant operation, regardless of permanence.”

With regard to skin, grafts typically consist of decellularized and/orreconstituted sheets of homogenized dermis that are used to achievetemporary, superficial wound coverage. Such grafts do not retain theoriginal tissue structure nor the metabolically active, otherwisenaturally present cells, and thus do not become vascularized; nocapillary ingrowth or vessel-to-vessel connections are made.Consequently, immune rejection is not a concern—the skin graft becomes“ejected” rather than rejected by the growth of a complete hostepithelium underneath the graft. Thus, while the term graft can becorrectly applied to such solutions, the primary qualities thatdifferentiate a transplant from a graft are that of heightenedcomplexity, organization, and inclusion of one or more types of tissue.In the present case, a skin transplant is fundamentally differentiatedfrom grafts known in the prior art. For example, a skin xenotransplantis comprised of live cells that perform the same function as thepatient's original skin before eventually experiencing immune-mediatedrejected. Thus, in this context, a skin xenotransplant according to thepresent disclosure is an organ transplant rather than a graft.

Product Characteristics and Therapeutic Uses

In some aspects, the xenotransplantation products described anddisclosed herein are temporary, i.e., their use in patients forxenotransplantation is non-permanent, utilized primarily for thetreatment of acute ailments and injuries, able to be utilized for longerperiods of time as compared to products that are not produced inaccordance with the present invention. It will be understood that someof the aspects of the products described and disclosed herein may alsobe permanent or more permanent, with transplanted organs, tissues and/orcells being accepted by human recipients over much longer periods oftime without adverse rejection.

In other aspects, the xenotransplantation products described anddisclosed herein are viable, live cell (e.g., vital, biologicallyactive) products; distinct from synthetic or other tissue-based productscomprised of terminally sterilized, non-viable cells which are incapableof completing the vascularization process. Further, in some aspects, theproduct of the present disclosure is not devitalized, or “fixed” withglutaraldehydes or radiation treatment.

In yet other aspects, the xenotransplantation products described anddisclosed herein are minimally manipulated (e.g., without physicalalteration of the related cells, organs or tissues) such that suchproducts are substantially in their natural state.

In yet other aspects, the xenotransplantation products described anddisclosed herein are capable of making an organic union with the humanrecipient, including, but not limited to, being compatible withvascularization, collagen growth (e.g., in regard to skin), and/or otherinteractions from the transplant recipient inducing graft adherence,organic union, or other temporary or permanent acceptance by therecipient.

In yet other aspects, the xenotransplantation products described anddisclosed herein are utilized in xenotransplantation without the need touse immunosuppressant drugs or other immunosuppressant therapies toachieve desired therapeutic results.

In other aspects, some of the xenotransplantation products described anddisclosed herein (e.g., skin) are stored by cryopreservation, storedfresh (without freezing), or stored via other methods to preserve suchproducts consistent with this invention. Storage involves usingconditions and processes that preserve cell and tissue viability.

In some aspects, storage may involve storing organs, tissues, or cells,in any combination of a sterile isotonic solution (e.g., sterile salinewith or without antibiotics), on ice, in a cryopreservation fluid,cryopreserved at a temperature of around −40° C. or around −80° C., andother methods known in the field. Such storage can occur in a primarycontainment system and secondary containment system.

In yet other aspects, the xenotransplantation products described anddisclosed herein are for homologous use, i.e., the repair,reconstruction, replacement or supplementation of a recipient's organ,cell and/or tissue with a corresponding organ, cell and/or tissue thatperforms the same basic function or functions as the donor (e.g., swinekidney is used as a transplant for human kidney, swine liver is used asa transplant for human liver, swine skin is used as a transplant forhuman skin, swine nerve is used as a transplant for human nerve and soforth).

In yet other aspects, the xenotransplantation products described anddisclosed herein have a low bioburden, minimizing pathogens, antibodies,genetic markers, and other characteristics that may serve to increasethe product's bioburden and the human body's immunological rejection ofthe product upon xenotransplantation. This may include the innate immunesystem, through PRRs TLRs, detecting PAMPs and rejecting the subjectxenotransplantation product.

It will be understood that the aspects disclosed and described hereincan be applied in any number of combinations to create an array ordifferent aspects comprising one or more of the features and/or aspectsof the aspects encompassed by the present invention.

It will be understood that there are numerous therapeutic applicationsfor products derived from DPF Closed Colony in accordance with thepresent invention. For example, such products may be utilized to treatacute and/or chronic disease, disorders, or injuries to organ, cells ortissue, and any and all other ailments that can utilize the productsdisclosed herein. Such treatments and/or therapies can include utilizingsuch products to repair, reconstruct, replace or supplement (in someaspects on a temporary basis and in other aspects a permanent basis), ahuman recipient's corresponding organ, cell and/or tissue that performsthe same basic function or functions as the donor.

Specific treatment applications include, but are not limited to, lungtransplants, liver transplants, kidney transplants, pancreastransplants, heart transplants, nerve transplants and other full orpartial transplants. With regard to skin, treatment applications alsoinclude, but are not limited to, treatment of burn wounds, diabeticulcerations, venous ulcerations, chronic skin conditions, and other skinailments, injuries and/or conditions (including, but not limited to,severe and extensive, deep partial and full thickness injuries, ailmentsand/or conditions) (see, e.g., Example 2 herein); use in adult andpediatric patients who have deep dermal or full thickness burnscomprising a total body surface area greater than or equal to 30%,optionally in conjunction with split-thickness autografts, or alone inpatients for whom split-thickness autografts may not be an option due tothe severity and extent of their wounds/burns; treatment of liverfailure, wounds, ailments, injuries and/or conditions with liverproducts derived in accordance with the present invention; treatment ofperipheral nerve damage, and other nerve ailments, injuries and/orconditions; and cell and other therapies utilizing materials harvestedfrom the DPF Closed Colony, including the therapeutic uses disclosed inU.S. Pat. No. 7,795,493 (“Phelps”), including cell therapies and/orinfusion for certain disorders (as disclosed in col. 30, line 1 to col.31, line 9) and treatment or certain disorders or pathologies (asdisclosed in col. 31, lines 10 to 42), the disclosure of which isincorporated by reference herein.

It will be understood that the specific recitation of therapies hereinin no way limits the types of therapeutic applications for the productsdisclosed and described herein, which encompass acute and/or chronicdisease, disorders, injuries to the following organs, tissues and/orcells: skin, kidneys, liver, brain, adrenal glands, anus, bladder,blood, blood vessels, bones, brain, brain, cartilage, ears, esophagus,eye, glands, gums, hair, heart, hypothalamus, intestines, largeintestine, ligaments, lips, lungs, lymph, lymph nodes and lymph vessels,mammary glands, mouth, nails, nose, ovaries, oviducts, pancreas, penis,pharynx, pituitary, pylorus, rectum, salivary glands, seminal vesicles,skeletal muscles, skin, small intestine, smooth muscles, spinal cord,spleen, stomach, suprarenal capsule, teeth, tendons, testes, thymusgland, thyroid gland, tongue, tonsils, trachea, ureters, urethra,uterus, uterus, vagina, areolar, blood, adenoid, bone, brown adipose,cancellous, cartaginous, cartilage, cavernous, chondroid, chromaffin,connective tissue, dartoic, elastic, epithelial, Epithelium, fatty,fibrohyaline, fibrous, Gamgee, Gelatinous, Granulation, gut-associatedlymphoid, Haller's vascular, hard hemopoietic, indifferent,interstitial, investing, islet, lymphatic, lymphoid, mesenchymal,mesonephric, mucous connective, multilocular adipose, muscle, myeloid,nasion soft, nephrogenic, nerve, nodal, osseous, osteogenic, osteoid,periapical, reticular, retiform, rubber, skeletal muscle, smooth muscle,and subcutaneous tissue; blood cells, blood precursor cells, cardiacmuscle cells, chondrocytes, cumulus cells, endothelial cells, epidermalcells, epithelial cells, fibroblast cells, granulosa cells,hematopoietic cells, Islets of Langerhans cells, keratinocytes,lymphocytes (B and T), macrophages, melanocytes, monocytes, mononuclearcells, neural cells, other muscle cells, pancreatic alpha-1 cells,pancreatic alpha-2 cells, pancreatic beta cells, pancreatic insulinsecreting cells, adipocytes, epithelial cells, aortic endothelial cells,aortic smooth muscle cells, astrocytes, basophils, bone cells, boneprecursor cells, cardiac myocytes, chondrocytes, eosinophils,erythrocytes, fibroblasts, glial cells, hepatocytes, keratinocytes,Kupffer cells, liver stellate cells, lymphocytes, microvascularendothelial cells, monocytes, neuronal stem cells, neurons, neutrophils,pancreatic islet cells, parathyroid cells, parotid cells, platelets,primordial stem cells, Schwann cells, smooth muscle cells, thyroidcells, tumor cells, umbilical vein endothelial cells, adrenal cells,antigen presenting cells, B cells, bladder cells, cervical cells, conecells, egg cells, epithelial cells, germ cells, hair cells, heart cells,kidney cells, leydig cells, lutein cells, macrophages, memory cells,muscle cells, ovarian cells, pacemaker cells, peritubular cells,pituitary cells, plasma cells, prostate cells, red blood cells, retinalcells, rod cells, Sertoli cells, somatic cells, sperm cells, spleencells, T cells, testicular cells, uterine cells, vaginal epithelialcells, white blood cells, ciliated cells, columnar epithelial cells,dopaminergic cells, dopaminergic cells, embryonic stem cells,endometrial cells, fibroblasts fetal fibroblasts, follicle cells, gobletcells, keratinized epithelial cells, lung cells, mammary cells, mucouscells, non-keratinized epithelial cells, osteoblasts, osteoclasts,osteocytes, and squamous epithelial cells. This listing is in no waymeant to limit the array of therapeutic uses to treat acute and/orchronic disease, disorders, injuries, organ or tissue failures, and anyand all other ailments that can utilize the products disclosed herein.

With respect to the treatment of burns, including but not limited toe.g., second- and third-degree burns, in some aspects, skin productsderived in accordance with the present invention are used to treat humanpatients with severe and extensive deep partial and/or full thicknessburn wounds. Such products contain terminally-differentiated cell typesthat are not expanded ex vivo prior to use and do not migrate from thesite of application during intended duration of treatment. Therefore,potential for tumorigenicity is negligible.

Such products adhere to the wound bed and provides a barrier function inthe immediate post-burn period. Such products have non-terminallysterilized, viable cells, allowing for vascularization of the grafttissue with the recipient. In some aspects, the epidermis remains fullyintact, and dermal components are maintained without change tostructural morphology or organization of the various cells and tissues.This physiologic mechanism supports the prolonged survival of the graftmaterial, and provides at least a temporary barrier function withsignificant clinical impact on par with, or better than, allograft. Insome aspects, if clinical signs of infection, e.g., pain, edema,erythema, warmth, drainage, odor or unexplained fever, are present ordeveloping, the product of the present disclosure is not applied untilthe clinical signs of the infection are reduced or eliminated for apredetermined period of time, e.g., 1, 2, 3, 4, 5, 6, or 7 days, 1, 2,3, or 4 weeks, or if the subject has tested negative for the infection.In some aspects, the wound is cleaned, confirmed to be well-vascularizedand nonexuding. If a dermal substitute such as cadaver allograft is alsobeing used, the epidermal layer is removed from engrafted allograftprior to the application of the product without removing the engrafteddermis. The epidermal layer may be removed with a dermatome or otherinstrument according to standard operating procedures of the facility.

Grafts conventionally used in clinical practice consist ofdecellularized and/or reconstituted sheets of homogenized dermis thatare used to achieve temporary, superficial wound coverage. Suchconventional grafts do not retain the original tissue structure nor themetabolically active, otherwise naturally present cells, and thus do notbecome vascularized; no capillary ingrowth or vessel-to-vesselconnections are made. In contrast, skin products described herein arefundamentally differentiated from such grafts because the product of thepresent disclosure includes live cells that perform the same function asthe patient's original skin, i.e., the product acts as an organtransplant. Skin performs additional, critical roles related tohomeostasis, temperature regulation, fluid exchange, and infectionprevention. The absence of a sufficient amount of skin can compromisethe ability to perform these functions leading to high incidences ofmortality and morbidity from infections and fluid loss. Skin transplantshave been reliably used with notable clinical benefit to prevent theseoutcomes in patients with significant wounds; regardless of whether thegraft is temporary or permanent. Thus, unlike other proposedtransplants, use of immunosuppressive drugs would not be necessary. Infact, such regimens would be contraindicated in burn patients whoseinjuries already exhibit some level of comprised immune function. Thus,the xenotransplantation product of the present disclosure should not beconfused with traditional “xenograft” products consisting ofeconstituted, homogenized wild-type porcine dermis fashioned into sheetsor meshed, such as EZ-Derm™ or Medi-Skin™. Such porcine xenografts donot vascularize and are primarily only useful for temporary coverage ofsuperficial burns. In stark contrast, the xenotransplantation product ofthe present disclosure contains metabolically active, minimallymanipulated cells in identical conformations and unchanged morphologiesas the source tissue.

In some aspects, the present disclosure includes using xenotransplanteddonor skin as a test for prediction of rejection of other organs fromthe same animal donor. Techniques for performing such predictive testsusing human donor skin have previously been described, e.g., in Moraeset al., Transplantation. 1989; 48(6):951-2; Starzl, et al., Clinical andDevelopmental Immunology, vol. 2013, Article ID 402980, 1-9; Roberto etal., Shackman et al., Lancet. 1975; 2(7934):521-4, the disclosures ofwhich are incorporated herein by reference in their entireties for allpurposes. Moraes reported that the crossmatch procedure was highlyaccurate in predicting early kidney transplant rejection. Shackmanreported that the fate of skin grafts taken from live human prospectivekidney donors correlates well with the outcome of kidney transplantationfrom the same donors. According to the present disclosure, in oneaspect, the present disclosure includes a method of using axenotransplanted skin sample in a human patient in order to determinewhether there is a risk of rejection of other organs xenotransplantedfrom the same animal donor in the human patient.

In some aspects, the xenotransplantation product of the presentdisclosure has pharmacokinetic and pharmacodynamics properties that meetregulatory requirements. Characterization of such properties requires aunique approach with respect to classical meanings of drug absorption,distribution, metabolism, and excretion. “Absorption” of thexenotransplantation product for the purposes of consideration ofpharmacokinetics, may be described by the vascularization process thexenotransplantation product experiences. For example, shortly aftersurgery, skin xenotransplantation products may present as warm, soft,and pink, whereas wild-type or traditional xenografts appear asnon-vascularized “white grafts.” In some aspects, the distribution ofthe transplant is limited to the site of transplant as confirmed by DNAPCR testing to demonstrate the presence or absence of pig cells inperipheral blood beyond the transplantation site.

In other aspects, the cells of the biological products produced inaccordance with the present invention do not migrate followingxenotransplantation into the recipient, including into the circulationof the recipient. This includes that PERV or PERV-infected porcine cellsdo not migrate into the recipient. Confirmation that such cells do notmigrate into the recipient can be performed in a number of ways,including via DNA-PCR analysis of peripheral blood mononuclear cells(PBMCs) and samples from the transplantation site and of highly perfusedorgans (e.g., liver, lung, kidney and spleen) to determine and otherwisedemonstrate that migrations of porcine cells (DNA) or porcine retroviral(RNA) components in the peripheral blood did not occur in the recipient.

Moreover, bioavailability and mechanism of action of thexenotransplantation product is not affected by size. The distribution ofthe xenotransplantation product is limited to the site of theadministration. For example, in the case of a skin transplant, thedebrided wound bed initially created by the trauma or burn injury is thesite of administration. The present disclosure includes testing todetect distribution of cells from the xenotransplantation product in theperipheral blood, wound beds, spleen and/or kidney beyond the site ofadministration. In certain aspects, such testing will demonstrate anabsence of cells from the xenotransplantation product in the peripheralblood, wound beds, spleen and/or kidney beyond the site ofadministration. Such testing may include DNA PCR testing for variouscellular markers present in the type of animal from which the product isobtained, e.g., PERV, swine MHC, and other swine DNA sequences. Incertain aspects, cells and nucleic acids from the xenotransplantationproduct remain limited to the site of administration.

The metabolism of the xenotransplantation product, traditionally definedas the metabolic breakdown of the drug by living organisms, typicallyvia specialized enzymes or enzymatic systems, may be congruent with theaforementioned natural host rejection phenomenon, which occurs in theabsence of exogenous immunosuppressive drugs. Via the same formulationand identical route of administration as intended for future human use,such xenotransplantation products undergo a delayed, immune rejectioncourse similar to allograft comparators for clinically useful durations.

In similar fashion, excretion of the xenotransplantation product couldbe modeled and experientially monitored by the clinical “sloughing”phenomenon as a result of necrotic ischemia of the transplant, due toantibody-mediated vascular injury, ultimately leading to the death ofthe tissue.

The demonstrated efficacy of the xenotransplantation product of thepresent disclosure, along with safety, availability, storage,shelf-life, and distribution, provide significant advantages overcurrent standards of care.

In some aspects, the “dosage” of the xenotransplantation product of thepresent disclosure is expressed as percentage of viable cells in theproduct per unit area of transplantation. As such, in some aspects, thexenotransplantation product of the present disclosure can be consideredas analogous to the active pharmaceutical ingredient in a pharmaceuticaldrug product.

Survival of the xenogeneic cells, tissues, or organs of the presentdisclosure is increased by avoiding: (a) infiltration of immune orinflammatory cells into the xenotransplantation product or alteration ofsuch cells in other relevant compartments, such as the blood andcerebrospinal fluid; (b) fibrotic encapsulation of thexenotransplantation product, e.g., resulting in impaired function orxenotransplantation product loss; (c) xenotransplantation productnecrosis; (d) graft versus host disease (GVHD); and (e) in vivo functionand durability of encapsulation or barriers intended to diminishrejection or inflammatory responses.

Blood samples from piglets are obtained and tested for phenotype, lackof expression of alpha galactose on the cell surface of blood cellsusing FITC-IB4 labeling and flow cytometry. At this stage ofdevelopment, all progeny will be genotyped at birth. A PCR assay hasbeen established to determine if a pig has a wild typegalactose-α1,3galactose transferase gene (Gal-T) or if it isheterozygous or homozygous for the Gal-T knockout (Gal-T-KO) using DNAisolated from ear notches or PBMC. Genomic DNA is isolated from PBMC (orskin tissues) using DNeasy Kit following the Qiagen DNeasy kitdirections. PCR is performed on genomic DNA and control template DNA,Wild type Gal-T (+/+) Heterozygote Gal-T-KO (+/−) and HomozygousGal-T-KO (−/−).

Punch biopsies of skin grafts are co-cultured with subconfluent targetcells, human 293 (kidney epithelium) and porcine ST-IOWA cell linesmaintained in culture medium (Dulbecco's modified Eagle's mediumsupplemented with 10% fetal bovine serum and glutamine, penicillin, andstreptomycin) in a 75-cm2 flask. The biopsies are kept in contact withthe target cells for 5 days, after which the culture medium andremaining tissue are removed and the target cell co-cultures aremaintained by subculturing as necessary. PERV infection of target cellsis determined by the presence of reverse transcriptase (RT) activity inthe culture supernatants. Transmission assays are maintained for aminimum of 60 days before being considered negative.

Product characterization to measure safety, identity, purity and potencyis performed. Safety tests include bacterial and fungal sterility,mycoplasma, and viral agents. The present disclosure includescryopreserving and archiving for further testing, as needed, samples ofall final xenotransplantation products (i.e., cells or tissues orbiopsies of organs), whether fresh or from culture ex vivo. In somecases, for example if the xenotransplantation product is a whole intactorgan, a relevant surrogate sample (e.g., adjacent tissues orcontra-lateral organ) is archived.

With regard to skin, storage and cryopreservation of porcine skin hasnot been fully characterized, especially with regards to viability, asmost porcine xenografts are intentionally devitalized, or “fixed” withglutaraldehydes or radiation treatment. Such information is necessary tosupport the use of vital porcine skin grafts—or porcine skintransplants—as a temporary and clinically advantageous option.

In procedures in which the xenotransplantation product is transplantedimmediately after removal from the source animal, such asxenotransplantation of whole organs, results of testing of thexenotransplantation product may not be available before its clinicaluse. In such cases, testing of the source animal, itself, may be all thetesting that is possible before the procedure. Testing of samples takenfrom such xenotransplantation products or appropriate relevantbiological surrogates, e.g., adjacent tissues or contra-lateral organs,may be performed according to the present disclosure. Microbiologicalexamination methods may include aspects set forth in the following Table3:

TABLE 3 SUITABILITY OF COUNTING METHOD IN THE PRESENCE TEST DETAILSGROWTH PROMOTION OF PRODUCT Preparation Total Aerobic Total Yeasts TotalAerobic Total Yeasts Microorganism of Test Strain Microbial Count andMolds Count Microbial Count and Molds Count StaphylococcusSoybean-Casein Soybean-Casein Soybean-Casein aureus such Digest AgarDigest Agar Digest Agar/ as ATCC or Soybean- and Soybean- MPN Soybean-6538, NCIMB Casein Digest Casein Digest Casein Digest 95 1 8, CIP BrothBroth ≤100 cfu Broth 100 cfu 4.83, or 30°-35° 30°-35° ≤3 days 30°-35° ≤3days NBRC 13276 18-24 hours Pseudomonas Soybean-Casein Soybean-CaseinSoybean-Casein aeruginosa Digest Agar Digest Agar Digest Agar/ such asATCC or Soybean- and Soybean- MPN Soyb ean- 9027, NCIMB Casein DigestCasein Digest Casein Digest 8626, CIP Broth Broth ≤100 cfu Broth ≤100cfu 82.118, or 30°-35° 30°-35° ≤3 days 30°-35° ≤3 days NBRC 13275 18-24hours Bacillus Soybean-Casein Soybean-Casein Soybean-Casein subtilissuch Digest Agar Digest Agar Digest Agar/ as ATCC or Soybean- andSoybean- MPN Soybean- 6633, NCIMB Casein Digest Casein Digest CaseinDigest 8054, CIP Broth Broth ≤100 cfu Broth ≤100 cfu 52.62, or 30°-35°30°-35° ≤3 days 30°-35° ≤3 days NBRC 3134 18-24 hours Candida SabouraudSoybean- Sabouraud Soybean- Casein Sabouraud albicans such DextroseCasein Digest Dextrose ≤100 cfu Digest Dextrose as ATCC Agar or Agar≤100 cfu 20°-25° ≤5 days Agar ≤100 cfu Agar ≤100 cfu 10231, NCPFSabouraud 30°-35° ≤5 days 30°-35° ≤5 days 20°-25° ≤5 days 3179, DextroseMPN: not IP 48.72, or Broth applicable NBRC 1594 20°-25° 2-3 daysAspergillus Sabouraud Soybean - Sabouraud Soybean - Casein Sabouraudbrasiiiensis Dextrose Agar Casein Digest Dextrose ≤100 cfu Digest Agar≤100 cfu Dextrose such as or Potato - Agar ≤100 cfu 20°-25° ≤5 days30°-35° ≤5 days Agar ≤100 cfu ATCC16404, Dextrose Agar 30°-35° ≤5 daysMPN: not 20°-25° ≤5 days IMI 149007, 20°-25° applicable IP 1431.83, or5-7 days, or NBRC 9455 until good sporulation is achieved

The present disclosure includes using Buffered Sodium Chloride-PeptoneSolution pH 7.0 or Phosphate Buffer Solution pH 7.2 to make testsuspensions; to suspend A. brasiliensis spores, 0.05% of polysorbate 80may be added to the buffer. The present disclosure includes using thesuspensions within 2 hours, or within 24 hours if stored between 2° C.and 8° C. As an alternative to preparing and then diluting a freshsuspension of vegetative cells of A. brasiliensis or B. subtilis, astable spore suspension is prepared and then an appropriate volume ofthe spore suspension is used for test inoculation. The stable sporesuspension may be maintained at 2° to 8° for a validated period of time.To verify testing conditions, a negative control is performed using thechosen diluent in place of the test preparation. There must be no growthof microorganisms. A negative control is also performed when testing theproducts as described under Testing of Products. A failed negativecontrol requires an investigation. Microbiological Examination may beperformed according to USP 61, USP 63, USP 71, USP 85 EP section 2.6.13Microbial Examination of Non-sterile Products (Test for SpecifiedMicroorganisms), each of which is incorporated herein by reference inits entirety.

With regard to testing for porcine cytomegalovirus (PCMV), sourceanimals are screened for PCMV on a quarterly basis. However, caesarianderived piglets, which are then consistently raised in the closed colonyare not infected with PCMV. Analysis for PCMV was conducted during thestudies in Example 1 herein and no PCMV was detected in the punchbiopsies using the following PCR method. These results were consistentto the PCR results from nasal swabs. Quantitative Real-Time PCR isutilized for PCMV testing. Target DNA sequences were quantified byreal-time PCR using a Stratagene Mx3005P. Sequence-specific primers andTaqMan probe were generated for each gene target. Each 25 uL PCRreaction included target DNA, 800 nM primers 200 nM TaqMan probe, 20 nMRox reference and 1× Brilliant III Ultra Fast Master Mix. The PCRcycling conditions were as follows: 1 cycle at 95° C. for 5 min followedby 50 cycles of denaturation at 95° C. for 10 seconds, andannealing-extension at 60° C. for 30 seconds with data collectionfollowing each extension. Serial dilutions of gel-extracted ampliconcloned into Invitrogen TOPO plasmid served as quantifying standards.Target DNA is detected with a linear dynamic range of 10 to 106 copies.For quantification of PCMV DNA, 300 ng of xenograft pig kidney DNA wasrun in a TaqMan PCR in triplicate. Primers and probes specific for PCMVDNA polymerase gene have been shown to have no cross-reactivity withPLHV-1. Utilization of cesarean-derived swine as source animals,combined with animal husbandry of the resulting closed colony andmaintenance of the barrier-isolation conditions is attributed theanimals being PCMV free. With regard to skin, the inventors noted thatthe safety and efficacy results achieved in Example 1 using singleknockout swine (as opposed to triple knockout or even furthergenetically modified swine) were quite surprising given the comparableperformance to allograft.

In some aspects, the analytical procedures used to test thexenotransplantation product can also include:

a. USP<71> Sterility. Samples are transferred to Tryptic Soy Broth (TSB)or Fluid Thioglycollate Medium (FTM) as appropriate. For Bacteriostasisand fungistasis, TSB samples are spiked with an inoculum of <100 ColonyForming Units (CFUs) of 24-hour cultures of Bacillus subtilis, Candidaalbicans, and with <100 spores of Aspergillus braseiliensis. The FTMsamples will be spiked with an inoculum of <100 CFU's of 24-hourcultures of Staphylococcus aureus, Pseudomonas aeruginosa, andClostridium sporogenes. If growth is not observed, the product is foundto be bacteriostatic or fungistatic and fails the USP <71> SterilityTest.

b. Aerobic and Anaerobic Bacteriological Cultures. Samples aretransferred to Tryptic Soy Broth (TSB) or Fluid Thioglycollate Medium(FTM) as appropriate. Vessels will be incubated to allow for potentialgrowth. If no evidence of microbial growth is found, the product will bejudged to comply with the test for sterility as described by USP<71>.

c. Mycoplasma Assay USP <63>. Fresh samples will be added to 100 mL ofMycoplasma Hayflick broth and incubated at 37° C. for up to 21 days. Thesample is subcultured after 2-4 days, 7-10 days, 14 days, and 21 days.The plates are then incubated at 37° C. for up to 14 days and checkedfor the presence of Mycoplasma colonies. If none are detected, theproduct is found to be in compliance with USP<63> and is mycoplasmafree.

d. Endotoxin USP<85>. Three samples from the same lot will be tested forthe Inhibition/Enhancement of the Limulus amoebocyte lysate (LAL) test.Samples will be extracted with 40 mL of WFI per sample at 37° C. for 1hour. Samples will then be tested in the LAL Kinetic Chromogenic Testwith a standard curve ranging from 5-50 EU/mL at a validated dilution.Assays will be performed in compliance with USP<85>.

e. MTT Assay for Cell Viability. The metabolic activity of the drugproduct is tested relative to control tissue samples using a biochemicalassay for [3-4,5 dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide(MTT) metabolism. Positive and negative control samples of freshxenotransplantation product tissue (positive control) or heatinactivated discs of xenotransplantation product tissue (negativecontrol) or the test article of Xenotransplantation product are placedin amber microcentrifuge tubes containing MTT solution (0.3 m g/mL inDMEM, 0.5 mL). The discs are treated with MTT formazan and incubated for180±15 minutes at 37° C. and an atmosphere of 5% CO 2 in air. Thereaction is terminated by removal of the discs and the formazan isextracted by incubation at either ambient temperature for <24 hours orrefrigerated at 4° C. for <72 hours. Samples are protected from lightduring this time. Aliquots are taken after the extraction is completeand the absorbance at 550 nm (with a reference wavelength of 630 nm) ismeasured and compared to a standard curve.

f. IB4 Assay for Extracellular Glycan Epitope. The absence of thegalactosyl-a-1,3-galactose (Alpha-Gal) epitope on cells will bedetermined using fluorescence activated flow cytometry. White bloodcells in whole blood are stained with a fluorochrome labeledisolectin-B4 (FITC-I-B4) and comparisons are made against blood obtainedfrom wild type positive controls and the Gal-T-KO source animal twice.First, all source animals are tested at birth. Second, the same testwill be performed from whole blood collected at sacrifice of the sourceanimal and tested for stability of the gene knockout, and the negativephenotype for Alpha-Gal. The isolectin binds to the epitope on cellsfrom the wild type pig but no binding occurs on the cells from theGal-T-KO pigs. The assay serves to confirm alpha-gal epitope is notpresent in the genetically engineered source animal. Spontaneousre-activation of the gene, and re-expression of the Alpha-Gal moietypost sacrifice is highly improbable and unreasonable to expect; itsinclusion would only deteriorate the efficacy of the xenotransplantationproduct causing it to resemble wild-type porcine tissue and hyperacutelyreject as previously demonstrated.

g. PERV Viral Assay. PERV pol quantitation 10 uL of a 1:625 dilution ofthe RT reaction was amplified in a 50 cycle PERV polymerase quantitativeTaqMan PCR in triplicate using a Stratagene MX300P real-timethermocycler (Agilent Technologies). 10 uL of a 1:25 dilution of the “NoRT enzyme” control RT reaction was similarly treated. PCR conditionsincluded PERV pol forward and reverse primers at 800 nM finalconcentration and PERV pol probe at 200 nM final concentration.Brilliant III Ultra Fast master mix (600880 Agilent Technologies) wasused supplemented to 20 nM with ROX reporter dye (600880 A gilentTechnologies) and 0.04 Units/μL UNG nuclease (N8080096, LifeTechnologies). Cycling conditions included 1 cycle of 10 minutes at 50°C. followed by one cycle of 10 minutes at 95° C. and 50 cycles of 10seconds at 95° C. followed by 30 seconds at 60° C. with data collectedat the end of each cycle. Absolute copies of PERV pol, and of porcineMHC-I and porcine GAPDH nucleic acids were measured per nanogram ofinput cDNA. Punch biopsies of thawed as described herein and washedxenotransplantation product are tested for the presence of PERV DNA andRNA.

h. Histology and Morphology. Samples of the xenotransplantation product,following the described manufacturing process, are sampled forexamination for cell morphology and organization. Verification undermicroscope via visible examination to ensure correct cell morphology andorganization of xenotransplantation product tissues and absent forabnormal cell infiltrate populations.

i. Release Assay Sampling Methodology. Once all units of the finalxenotransplantation product lot have been created, units areindependently, randomly selected for use in manufacturing release assaysfor the required acceptance criteria. These units will be marked for lotrelease to the various laboratory contractors, and the variousanalytical tests will be performed per the required cGMP conditions.

Similarly, prior to validation for human clinical use, all finalxenotransplantation product must meet acceptance criteria for selectinga donor pig for material including (i) reviewing the medical record fora defined pedigree, (ii) reviewing the medical record for the testresults for alpha-1,3-galactose by Flowmetrics, (iii) reviewing themedical record for a history of full vaccinations; (iv) reviewing themedical record for the surveillance tests performed over the lifetime ofthe pig; (v) adventitious agent screening of source animal; (vi)reviewing the medical record for infections over the lifetime of thepig; and (vi) reviewing the medical record for any skin abnormalitiesnoted in the animal's history.

The final xenotransplantation product control strategy and analyticaltesting is conducted at the conclusion of the manufacturing processprior to release for clinical use. Results of the required analyticaltests will be documented via a xenotransplantation product drug productCertificate of Analysis (COA) that is maintained with a master batchrecord pertaining to each lot of xenotransplantation product drugproduct.

The following Table 4 is a list of the assays and results of the batteryof tests performed on the xenotransplantation product materials.

TABLE 4 Sample Material Test Test Method Tested Result Sterility TestingTissue Culture 3 mm Punch No growth detected Aerobic Bacteria Biopsy ofAnaerobic Bacteria Xenotransplantation Fungi product Acid fast cultures(Post Thaw) Specific bacterial screen Mycological Screen MycoplasmaAssay 3 mm Punch No growth Biopsy of detected after 28Xenotransplantation days product (Post Thaw) Bacteriostasis & USP<71>Xenotransplantation Bacteriostatic, no Fungistasis Gibraltar Laboratoryproduct growth of specific (Post Thaw) indicator organism Endotoxin TestUSP<85> LAL, Xenotransplantation <0.2 EU/unit Kinetic productChromogenic Test (Post Thaw) Endogenous Viral Testing RT-qPCR 3 mm PunchPresence of (PERV) Co-culture Assay Biopsy of PERV A, B, C MGH -Xenotransplantation confirmed Infectious product Disease - (Post Thaw)Fishman Laboratory Viability Testing MTT and 3 mm Punch Greater than 70%Phenyl Acetate Biopsy of Mitochondrial Assays XenotransplantationActivity remaining product following freeze-thaw (Post Thaw) cycle,confirmed by both assays Identity Histology, 3 mm Punch No abnormalitiesCell Morphology Hematoxylin and Biopsy of noted. Eosin StainingXenotransplantation Cell morphology product and organization (Post Thaw)consistent with skin graft No presence of Alpha- GAL detectedConfirmation Flow Cytometry, Whole Blood, 2 of absence of isolectin-B4(FITC- ml, obtained Alpha-GAL I- B4) from source (Gal-T- animal, atKnockout sacrifice. confirmation)

In another aspect it will be understood that there includes anadventitious agent control strategy developed based on the sourceanimal, including the species, strain, geographic origin, type oftissue, and proposed indication. Analytical Tests are conducted foradventitious agents, to include bacteria, fungi, mycoplasma, and viralmicroorganisms, including as follows:

a. Bacteriological Free Status—The bacteriological screen is conductedto confirm the drug product is free of potential biological agents ofconcern Humans. Both Aerobic and Anaerobic screens are conducted toensure sterility. Samples are thawed as described herein and transferredto Tryptic Soy Broth (TSB) or Fluid Thioglycollate Medium (FTM) asappropriate. Vessels will be incubated to allow for potential growth. Ifno evidence of microbial growth is found, the product will be judged tocomply with the test for sterility.

b. Mycological (Fungal) Free Status—The mycological screen is conductedto confirm the Drug Product is free of potential fungal agents ofconcern. Samples are thawed as described herein. After thawing, samplesare transferred to a soybean-casein digest agar. Vessels will beincubated to allow for potential growth. If no evidence of fungal growthis found, the product will be judged to comply with the test forsterility per USP<71>.

c. Mycoplasma Free Status—The mycoplasma screen is conducted to confirmthe drug product is free of mycoplasma. Samples are thawed as describedherein and added to 100 mL of Mycoplasma broth and incubated at 37° C.for up to 21 days. The sample is subcultured after 2-4 days, 7-10 days,14 days, and 21 days. The plates are then incubated at 37° C. for up to14 days and checked for the presence of Mycoplasma colonies. If none aredetected, the product is found to be in compliance with USP<63> and ismycoplasma free.

d. Endotoxin Free Status—The endotoxin free status is conducted toconfirm the drug product is free of endotoxins and related agents ofconcern. Three samples from the same lot will be tested for theInhibition/Enhancement of the Limulus amoebocyte lysate (LAL) test.Samples will be thawed as described herein and extracted with 40 mL ofWFI per sample at 37° C. for 1 hour. Samples will then be tested in theLAL Kinetic Chromogenic Test with a standard curve ranging from 5-50EU/mL at a validated dilution. Assays will be performed in compliancewith USP<85>.

e. Viral Assays Conducted—The viral assays are conducted to confirm thesource animal is free of potential viral agents of concern, confirmationof endogenous viruses (see below). This includes co-culturing and RT-PCRtesting for specific latent endogenous viruses including PERV. In vivoassays are also conducted on the animal source to monitor animal healthand freedom from viral infection as key aspects of the lot releasecriteria. Due to the endemic nature of PERV in porcine tissue, thisqualifies as a positive result that does not preclude the use of suchtissue. However, the virus is identified and characterized in lotrelease to provide information for monitoring the recipient of thexenotransplantation product.

f. Cell Viability Assay—The MTT assay is conducted to confirm thebiologically active status of cells in the xenotransplantation product.Evidence of viability is provided through surrogate markers ofmitochondrial activity as compared to positive (fresh, notcryopreserved) and negative (heat-denatured) controls. The activity ofthe cells is required for the xenotransplantation product to afford theintended clinical function. This is required as a lot release criteria,and is currently established that tissue viability should not be lessthan 50% of the metabolic activity demonstrated by the fresh tissuecontrol comparator.

g. Histology and Morphology—Verification under microscope via visibleexamination of Hematoxylin and Eosin (H&E) section staining of theepidermal and dermal layers, to ensure correct cell morphology andorganization of the xenotransplantation product tissues and cellinfiltrate populations. This is conducted to confirm the appropriatephysiologic appearance and identity of cells present in thexenotransplantation product. The xenotransplantation product is composedof minimally manipulated porcine dermal and epidermal tissue layers.This is required as a lot release criteria. Evidence of the followingcell layers (from most superficial to deepest), in the epidermal layerare verified:

-   -   i. Stratum Corneum    -   ii. Stratum Granulosum    -   iii. Stratum Spinosum    -   iv. Stratum Basale        Evidence of the following cellular structures in the dermal        layer are verified:    -   v. Blood vessels, evidence of vasculature    -   vi. Nerves    -   vii. Various glands    -   viii. Hair follicles    -   ix. Collagen

The genetically engineered source animals do not contain any foreign,introduced DNA into the genome; the gene modification employed isexclusively a knock-out of a single gene that was responsible forencoding for an enzyme that causes ubiquitous expression of acell-surface antigen. It will be understood that the xenotransplantationproduct in one or more aspects do not incorporate transgenetechnologies, such as CD-46 or CD-55 transgenic constructs.

An endotoxin free status is conducted to confirm the drug product isfree of endotoxins and related agents of concern. Protocols for theassurance of Endotoxin free status are as follows: Three samples fromthe same lot are tested for Inhibition/Enhancement of the Limulusamoebocyte lysate (LAL) test. Samples are thawed, extracted, and testedin the LAL Kinetic Chromogenic Test with a standard curve ranging from5-50 EU/mL at a validated dilution in compliance with USP<85>.

The MTT assay is conducted to confirm the biologically active status ofcells in the product. Evidence of viability is provided throughsurrogate markers of mitochondrial activity as compared to positive(fresh, not cryopreserved) and negative (heat-denatured) controls. Theactivity of the cells is required for the product to afford the intendedclinical function and the viability parameters for one aspect rangingfrom 50% to 100% mitochondrial activity.

Verification under microscope via visible examination of Hematoxylin andEosin (H&E) section staining of the epidermal and dermal layers, toensure correct cell morphology and organization of thexenotransplantation product tissues and cell infiltrate populations.This is conducted to confirm the appropriate physiologic appearance andidentity of cells present in the product.

For skin xenotransplantation products, evidence of the following celllayers (from most superficial to deepest), in the epidermal layer areverified: Stratum Corneum; Stratum Granulosum; Stratum Spinosum; StratumBasale. Evidence of the following cellular structures in the dermallayer are verified: Blood vessels, evidence of vasculature; Nerves;Various glands; Hair follicles; Collagen.

The xenotransplantation product may be further processed to ensure thatit remains free of aerobic and anaerobic bacteria, fungi, viruses, andmycoplasma. Under sterile conditions in a laminar flow hood in a drugproduct processing suite using applicable aseptic techniques,immediately after, within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 seconds, within10 seconds to 1 minute, within 1 minute to 1 hour, within 1 hour to 15hours, or within 15 hours to 24 hours following harvest, thexenotransplantation product is sterilized, e.g., using one or more of UVirradiation or an anti-microbial/anti-fungal. In one aspect, the productmay be placed into an anti-microbial/anti-fungal bath (“antipathogenbath”). The antipathogen bath may include: one or more anti-bacterialagents, e.g., ampicillin, ceftazidime, neomycin, streptomycin,chloramphenicol, cephalosporin, penicillin, tetracycline, vancomyocin,and the like; one or more anti-fungal agents, e.g., amphotericin-B,azoles, imidazoles, triazoles, thiazoles, candicidin, hamycin,natamycin, nystatin, rimocidin, allylamines, echinocandins, and thelike; and/or one or more anti-viral agents. The anti-pathogen bath mayinclude a carrier or medium as a diluent, e.g., RPMI-1640 medium. Insome aspects, the anti-pathogen bath may include at least 2anti-bacterial agents. In some aspects, the anti-pathogen bath mayinclude at least 2 anti-bacterial agents and at least one anti-fungalagent. In some aspects, the anti-pathogen bath may include at least fouragents. In some aspects, the anti-pathogen bath may include no more than4, 5, 6, 7, 8, 9, or 10 agents. In some aspects, the anti-pathogen bathmay include any combination of the foregoing.

The product may be sterilized using UV light sterilization. For example,the product is placed under the UV lamp for a desired period of time,e.g., 0.5, 1, 1.5, 2, 3, 4, 5, 6, minutes or more, then turned over tothe other side, and put under the UV lamp for the same or a differentperiod of time on opposite side. The time period for exposing a givensample to the UV may be varied based on the specific biological agentsor the types of biological agents to be sterilized, e.g., as shown inthe following Table 8 below. For example, the product may be sterilizedusing a UV lamp having a UV-C intensity of at least 100 uW/cm² for atleast 2 minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or 2.5 minutes, andturned over such that its opposite surface is exposed to the UV lamp forat least 2 minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or 2.5 minutesto obtain a UV-treated product; a UV-C dosage of at least 100,000 uWsec/cm² and up to 800,000, 700,000, 600,000, 500,000, 400,000, 300,000or 200,000 uW sec/cm²; a UV-C dosage of at least 200,000 uW sec/cm² andup to 800,000, 700,000, 600,000, 500,000, 400,000, or 300,000 uWsec/cm²; a UV lamp having a UV-C intensity of at least 100 uW/cm² for atleast 2 minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or 2.5 minutes.

Product processing occurs in a single, continuous, and self-contained,segregated manufacturing event that begins with the sacrifice of thesource animal through completion of the production of the final product.The animal is euthanized via captive bolt euthanasia, may be moved, ifnecessary, in a sterile, non-porous bag, to an operating room where theprocedure to harvest biological product from the source animal willoccur. All members of the operating team should be in full sterilesurgical gear, e.g., dressed in sterile dress to maintain designatedpathogen free conditions prior to receiving the source animal and insome instanced be double-gloved to minimize contamination, and surgicalareas and tools are sterilized. The source animal is removed from thebag and container in an aseptic fashion. The source animal is scrubbedby operating staff, e.g., for at least 1-10 minutes with antiseptic,e.g., Chlorhexidine, brushes over the entire area of the animal wherethe operation will occur, periodically pouring Chlorhexidine over thearea to ensure coverage. Surgical area(s) of the animal are scrubbedwith opened Betadine brushes and sterile water rinse over the entirearea of the animal where the operation will occur for, e.g., 1-10minutes.

In one aspect, with regard to skin, a full thickness skin graft wounddressing consisting of dermal tissue derived from a swine in accordancewith the present invention is used in conjunction or combination withcultured epidermal autografts to produce a product according to thepresent disclosure and that can be used in methods of the presentdisclosure. Prior to application of the epidermal autografts,significant debridement of wound bed is required to ensure an adequatesubstrate. To confirm a wound bed is ready for an epidermal autograft,apply the skin products described herein, e.g., biological skin productsderived from animals of the present disclosure to confirm adherence.Once adherence is confirmed, the temporary wound coverage product isremoved, and in some aspects, the wound bed is covered with a meshedautograft, and one or more cultured epidermal autograft products areplaced on top to close the gaps in the autograft mesh.

The debridement may include mechanical debridement, chemicaldebridement, enzymatic debridement, or a combination thereof. Mechanicaldebridement may include surgical excision, e.g., tangential excision toremove thin layers of dermis until healthy tissue is visualized, orfascial excision to remove the full thickness of dermis down to theunderlying fascia. Tangential excision allows less viable tissue to beremoved with the necrotic tissue, but typically results in higher bloodloss, is a larger physiologic stressor than fascial excision, and ismore likely to result in “incomplete” debridement, with some devitalizedtissue remaining in place. In fascial excision, blood loss and operativetime are minimized, but often a large amount of healthy tissue isremoved with the burned tissue. Debriding agents may include agentscapable of cleaning a burn wound by removing foreign material and deadtissue. Many such agents are known. In enzymatic debridement,collagenases or other proteolytic enzymes are employed that break downproteins of the extracellular matrix, allowing devitalized tissue to bewiped away without the need for surgery while preferably leaving healthytissue substantially intact. Enzymatic debridement involves theapplication of proteolytic and optionally other exogenous enzymes to awound surface to break down necrotic tissue. Enzymatic debridement maybe a relatively slow process, carried out over a period of a number ofweeks in combination with other topical preparations, soakings andrepeated dressings. Alternately, rapid enzymatic debridement can beaccomplished using multi-enzyme products, for example, those extractedfrom the stem of the pineapple plant, as disclosed for example in WO98/053850 and WO 2006/0006167, and as provided in the product marketedunder the trade name Debrase®. A procedure for enzymatic debridementgenerally utilizes an enzyme such as bromelain derivatives, debridase,collagenase, papain derivatives, streptokinase, sutilains, fibrinolysin,deoxyribonuclease, hill derivatives, trypsin or combinations thereof.Autolytic debridement relies on enhancing the natural process ofselective liquefaction, separation and digestion of necrotic tissue andeschar from healthy tissue that occurs in wounds due to macrophage andendogenous proteolytic activity. This is achieved by the use ofocclusive, semi-occlusive or moist interactive dressings. Enzymaticdebridement agents include a bromelain enriched enzyme product, othercollagenases, or other enzyme products capable of clearing devitalizedtissue or wound debris. NexoBrid™ (MediWound Ltd.) is one such bromelainenriched product that specifically targets heat-denatured collagen fordegradation, resulting in partial-thickness and full-thickness woundsrequiring a wound coverage or dressing product. Such products andmethods are described in U.S. Pat. Nos. 8,540,983; 8,119,124; 7,128,719;7,794,709; 8,624,077; and US2009/0010910A1, each of which isincorporated by reference herein.

In some aspects, the wound bed may include or be a chronic wound or anacute wound. Chronic wounds include but are not limited to venous legulcers, pressure ulcers, and diabetic foot ulcers. Acute wounds includebut are not limited to burns, traumatic injuries, amputation wounds,skin graft donor sites, bite wounds, frostbite wounds, dermabrasions,and surgical wounds.

In the cases where there is no dermis, biological products produced inaccordance with the present invention are utilized. The epidermis isremoved from such products (e.g., before dermis harvesting on the pigwith a VERSAJET™ Hydrosurgery system), so that just the dermis remains.Then, the subject biological product is placed on the patient'ssubcutaneous tissue, serving as a substrate for the cultured epidermalautograft process described herein.

In one aspect, a liver derived in accordance with the present disclosureis utilized for extracorporeal perfusion as a temporary filter for ahuman patient until a patient receives a human transplant. In anoperating area within the DPF Isolation Area, a source animal is placedunder a general anesthetic (ketamine, xylazine, enflurane) or euthanizedby captive bolt. A hepatectomy is then performed on the source animal indesignated pathogen free conditions. The liver product derived from thesource animal can be packaged and transported to the location of theprocedure in accordance with current practice with human donor livers.The procedure to utilize the liver filtration product can be performed,for example, by percutaneously cannulating a human patient's internaljugular vein for venous return with an arterial cannula andpercutaneously cannulating a patient's femoral vein for venous outflowwith an artery cannula. These cannulas are connected to a bypasscircuit, having a centrifugal pump, a heat exchanger, an oxygenator, anda roller pump incorporated therein. This circuit is primed withcrystalloids and run for a period of time (e.g., 10-30 minutes) beforethe liver from an animal according to the present disclosure isincorporated at a stabilized flow rate, e.g., 600-1000 ml/min,maintained in a crystalloid bath occasionally supplemented with warmsolution, e.g., 30-40° C.

It will be understood that, in the context of swine-to-humanxenotransplantation, each human recipient will have a majorhistocompatibility complex (MHC) (Class I, Class II and/or Class III)that is unique to that individual and will not match the MHC of thedonor swine. Accordingly, it will be understood that when a donor swinegraft is introduced to the recipient, the swine MHC molecules themselvesact as antigens, provoking an immune response from the recipient,leading to transplant rejection.

Human leukocyte antigen (HLA) genes show incredible sequence diversityin the human population. For example, there are >4,000 known alleles forthe HLA-B gene alone. The genetic diversity in HLA genes in whichdifferent alleles have different efficiencies for presenting differentantigens is believed to be a result of evolution conferring betterpopulation-level resistance against the wide range of differentpathogens to which humans are exposed. This genetic diversity alsopresents problems during xenotransplantation where the recipient'simmune response is the most important factor dictating the outcome ofengraftment and survival after transplantation.

In accordance with one aspect the present invention, a donor swine isprovided with a genome that is biologically engineered to express aspecific set of known human HLA molecules. Such HLA sequences areavailable, e.g., in the IPD-IMGT/HLA database (available atebi.ac.uk/ipd/imgt/hla/) and the international ImMunoGeneTicsInformation System® (available at imgt.org). For example, HLA-A1, B8,DR17 is the most common HLA haplotype among Caucasians, with a frequencyof 5%. Thus, the disclosed method can be performed using the knownMHC/HLA sequence information in combination with the disclosuresprovided herein.

In some aspects, the recipient's human leukocyte antigen (HLA) genes andMHC (Class I, II and/or III), are identified and mapped. It will beunderstood that ascertaining the human recipient's HLA/MHC sequence canbe done in any number of ways known in the art. For example, HLA/MHCgenes are usually typed with targeted sequencing methods: eitherlong-read sequencing or long-insert short-read sequencing.Conventionally, HLA types have been determined at 2-digit resolution(e.g., A*01), which approximates the serological antigen groupings. Morerecently, sequence specific oligonucleotide probes (SSOP) method hasbeen used for HLA typing at 4-digit resolution (e.g., A*01:01), whichcan distinguish amino acid differences. Currently, targeted DNAsequencing for HLA typing is the most popular approach for HLA typingover other conventional methods. Since the sequence-based approachdirectly determines both coding and non-coding regions, it can achieveHLA typing at 6-digit (e.g., A*01:01:01) and 8-digit (e.g.,A*01:01:01:01) resolution, respectively. HLA typing at the highestresolution is desirable to distinguish existing HLA alleles from newalleles or null alleles from clinical perspective. Such sequencingtechniques are described in, for example, Elsner H A, Blasczyk R: (2004)Immunogenetics of HLA null alleles: implications for blood stem celltransplantation. Tissue antigens. 64 (6): 687-695; Erlich R L, et al(2011) Next-generation sequencing for HLA typing of class I loci. BMCgenomics. 12: 42-10.1186/1471-2164-12-42; Szolek A, et al. (2014)OptiType: Precision HLA typing from next-generation sequencing data.Bioinformatics 30:3310-3316; Nariai N, et al. (2015) HLA-VBSeq: AccurateHLA typing at full resolution from whole-genome sequencing data. BMCGenomics 16:S7; Dilthey A T, et al. (2016) High-accuracy HLA typeinference from whole-genome sequencing data using population referencegraphs. PLoS Comput Biol 12:e1005151; Xie C., et al. (2017) Fast andaccurate HLA typing from short-read next-generation sequence data withxHLA 114 (30) 8059-8064, each of which is incorporated herein in itsentirety by reference.

The known human HLA/MHC or an individual recipient's sequenced HLA/MHCsequence(s) may be utilized as a template to modify the swine leukocyteantigen (SLA)/MHC sequence to match, e.g., to have 90%, 95%, 98%, 99%,or 100% sequence homology to a known human HLA/MHC sequence or the humanrecipient's HLA/MHC sequence. Upon identifying a known human recipientHLA/MHC sequence to be used or performing genetic sequencing of a humanrecipient to obtain HLA/MHC sequences, biological reprogramming may beperformed to SLA/MHC sequences in cells of the swine based on desiredHLA/MHC sequences. For example, several targeting guide RNA (gRNA)sequences are administered to the swine of the present disclosure toreprogram SLA/MHC sequences in cells of the swine with the templateHLA/MHC sequences of the human recipient.

CRISPR-Cas9 is used to mediate rapid and scarless exchange of entire MHCalleles at specific native locus in swine cells. Multiplex targeting ofCas9 with two gRNAs is used to introduce single or double-strandedbreaks flanking the MHC allele, enabling replacement with the templateHLA/MHC sequence (provided as a single or double-stranded DNA template).In certain aspects, the CRISPR/Cas9 components are injected into swineoocytes, ova, zygotes, or blastocytes prior to transfer into fostermothers.

In certain aspects, the present disclosure includes embryogenesis andlive birth of SLA-free and HLA-expressing biologically reprogrammedswine. In certain aspects, the present disclosure includes breedingSLA-free and HLA-expressing biologically reprogrammed swine to createSLA-free and HLA-expressing progeny. In certain aspects, the CRISPR/Cas9components are injected into swine zygotes by intracytoplasmicmicroinjection of porcine zygotes. In certain aspects, the CRISPR/Cas9components are injected into swine prior to selective breeding of theCRISPR/Cas9 genetically modified swine. In certain aspects, theCRISPR/Cas9 components are injected into donor swine prior to harvestingcells, tissues, zygotes, and/or organs from the swine. In certainaspects, the CRISPR/Cas9 components include all necessary components forcontrolled gene editing including self-inactivation utilizing governinggRNA molecules as described in U.S. Pat. No. 9,834,791 (Zhang), which isincorporated herein by reference in its entirety.

The genetic modification can be made utilizing known genome editingtechniques, such as zinc-finger nucleases (ZFNs), transcriptionactivator-like effector nucleases (TALENs), adeno-associated virus(AAV)-mediated gene editing, and clustered regular interspacedpalindromic repeat Cas9 (CRISPR-Cas9). These programmable nucleasesenable the targeted generation of DNA double-stranded breaks (DSB),which promote the upregulation of cellular repair mechanisms, resultingin either the error-prone process of non-homologous end joining (NHEJ)or homology-directed repair (HDR), the latter of which can be used tointegrate exogenous donor DNA templates. CRISPR-Cas9 may also be used toremove viral infections in cells. For example, the genetic modificationvia CRISPR-Cas9 can be performed in a manner described in Kelton, W. et.al., “Reprogramming MHC specificity by CRISPR-Cas9-assisted cassetteexchange,” Nature, Scientific Reports, 7:45775 (2017) (“Kelton”), theentire disclosure of which is incorporated herein by reference.Accordingly, the present disclosure includes reprogramming usingCRISPR-Cas9 to mediate rapid and scarless exchange of entire alleles,e.g., MHC, HLA, SLA, etc.

In one aspect, the recipient's HLA/MHC gene is sequenced and templateHLA/MHC sequences are prepared based on the recipient's HLA/MHC genes.In another aspect, a known human HLA/MHC genotype from a WHO databasemay be used for genetic reprogramming of swine of the presentdisclosure. CRISPR-Cas9 plasmids are prepared, e.g., using polymerasechain reaction and the recipient's HLA/MHC sequences are cloned into theplasmids as templates. CRISPR cleavage sites at the SLA/MHC locus in theswine cells are identified and gRNA sequences targeting the cleavagesites and are cloned into one or more CRISPR-Cas9 plasmids. CRISPR-Cas9plasmids are then administered into the swine cells and CRIPSR/Cas9cleavage is performed at the MHC locus of the swine cells.

The SLA/MHC locus in the swine cells are replaced with one or moretemplate HLA/MHC sequences matching the known human HLA/MHC sequences orthe recipient's sequenced HLA/MHC genes. Cells of the swine aresequenced after performing the SLA/MHC reprogramming steps in order todetermine if the HLA/MHC sequences in the swine cells have beensuccessfully reprogrammed. One or more cells, tissues, and/or organsfrom the HLA/MHC sequence-reprogrammed swine are transplanted into ahuman recipient.

In certain aspects, HLA/MHC sequence-reprogrammed swine are bred for atleast one generation, or at least two generations, before their use as asource for live tissues, organs and/or cells used inxenotransplantation. In certain aspects, the CRISPR/Cas9 components canalso be utilized to inactivate genes responsible for PERV activity,e.g., the pol gene, thereby simultaneously completely eliminating PERVfrom the swine donors.

For purposes of modifying donor SLA/MHC to match recipient HLA/MHC,comparative genomic organization of the human and swinehistocompatibility complex has been mapped. For example, such SLA to HLAmapping can be found in: Lunney, J., “Molecular genetics of the swinemajor histocompatibility complex, the SLA complex,” Developmental andComparative Immunology 33: 362-374 (2009) (“Lunney”), the entiredisclosure of which is incorporated herein by reference. Accordingly, aperson of ordinary skill in the art effectively and efficientlygenetically reprogram swine cells in view of the present disclosure andusing the mapping of Lunney et al. as a reference tool.

The modification to the donor SLA/MHC to match recipient HLA/MHC causesexpression of specific MHC molecules from the swine cells that areidentical, or virtually identical, to the MHC molecules of a known humangenotype or the specific human recipient. In one aspect, the presentdisclosure involves making modifications limited to only specificportions of specific SLA regions of the swine's genome to retain aneffective immune profile in the swine while biological products arehypoimmunogenic when transplanted into human recipients such that use ofimmunosuppressants can be reduced or avoided. In contrast to aspects ofthe present disclosure, xenotransplantation studies of the prior artrequired immunosuppressant use to resist rejection. In one aspect, theswine genome is reprogrammed to knock-out swine genes corresponding toHLA-A, HLA-B, HLA-C, and DR, and to knock-in HLA-C, HLA-E, HLA-G. Insome aspects, the swine genome is reprogrammed to knock-out swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and to knock-inHLA-C, HLA-E, HLA-G. In some aspects, the swine genome is reprogrammedto knock-out swine genes corresponding to HLA-A, HLA-B, HLA-C, HLA-F,DQ, and DR, and to knock-in HLA-C, HLA-E, HLA-G, HLA-F, and DQ. In oneaspect, the swine genome is reprogrammed to knock-out SLA-11; SLA-6,7,8;SLA-MIC2; and SLA-DQA; SLA-DQB1; SLA-DQB2, and to knock-in HLA-C; HLA-E;HLA-G; and HLA-DQ. In certain aspects, HLA-C expression is reduced inthe reprogrammed swine genome. By reprogramming the swine cells to beinvisible to a human's immune system, this reprogramming therebyminimizes or even eliminates an immune response that would haveotherwise occurred based on swine MHC molecules otherwise expressed fromthe donor swine cells.

It will therefore be understood that this aspect (i.e., reprogrammingthe SLA/MHC to express specifically selected human MHC alleles), whenapplied to swine cells, tissues, and organs for purposes ofxenotransplantation will decrease rejection as compared to cells,tissues, and organs derived from a wild-type swine or otherwisegenetically modified swine that lacks this reprogramming, e.g.,transgenic swine or swine with non-specific or different geneticmodifications.

It will be further understood that causing the donor swine cells,tissues, and organs to express a known human MHC genotype or therecipient's MHC specifically as described herein, combined with theelimination in the donor swine cells of alpha-1,3-galactosytransferase,Neu5Gc, and β1,4-N-acetylgalactosaminyltransferase (B4GALNT2) (e.g.,“single knockout,” “double knockout,” or “triple knockout”), presents aswine whose cells will have a decreased immunological rejection ascompared to a triple knockout swine that lacks the specific SLA/MHCreprogramming of the present disclosure.

Cryopreservation and storage according to the present disclosureincludes preparing biological product according to the presentdisclosures, placing in a container, adding freeze media to thecontainer and sealing. For example. 15% dimethyl sulfoxide (DMSO)cryoprotective media is combined with fetal porcine serum (FPS) or donorserum (if FPS is unavailable) in a 1:1 ratio, filtered (0.45 micron),and chilled to 4° C. prior to use. The containers are subsequentlyfrozen in a controlled rate, phase freezer at a rate of 1° C. per minuteto −40° C., then rapidly cooled to a temperature −80° C. DMSO displacesintracellular fluid during the freezing process. Cryoprotective media,e.g., CryoStor is used in an amount of about 40-80%, or 50-70% based onmaximum internal volume of the cryovial (10 ml) less the volume of thexenotransplantation product. In order to thaw the cryopreservedbiological product for surgical use, sealed vials were placed in ˜37° C.water baths for approximately 0.5 to 2 minutes, at which point thecontainer is opened and the product was removed using sterile technique.Subsequently, products undergo three, 1-minute serial washes, e.g., insaline with gentle agitation, in order to dilute and systematicallyremove ambient, residual DMSO and prevent loss of cell viability. Theproduct may then be used surgically.

It will be understood that the xenotransplantation product may beprocessed, stored, transported, and/or otherwise handled usingmaterials, containers and processes to ensure preserved sterility andprevent damage thereto. In some aspects, a sterile non-adhesive materialmay be used to protect the xenotransplantation product, e.g., to supportthe xenotransplantation product and prevent adhesive of the product tosurfaces and/or to prevent self-adhesion of the xenotransplantationproduct during manipulation, storage, or transport. Unintentionaladhesion of the xenotransplantation product may disrupt the integrity ofthe xenotransplantation product and potentially reduce its therapeuticviability. Inclusion of the sterile non-adhesive material providesprotection and/or physical support and prevents adhesion. In someaspects, the sterile non-adhesive material is not biologically orchemically active and does not directly impact the metabolic activity orefficacy of the xenotransplantation product itself.

Aspects of the present disclosure are further described by the followingnon-limiting list of items:

1. A method of producing a biological product suitable forxenotransplantation into a human recipient comprising:

producing a non-wild type, biologically engineered swine, wherein saidswine is produced through natural breeding and natural birthing, whereinsaid swine has a biologically engineered genome such that it does notexpress one or more extracellular surface glycan epitopes, and whereinsaid swine is free of at least the following pathogens: Ascaris species,cryptosporidium species, Echnococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, pseudorabies, Toxoplasma Gondii, staphylococcus species,Microphyton species, and Trichophyton species, porcine influenza,cytomegalovirus, arterivirus, and coronavirus,

rearing the swine and maintaining the swine according to abioburden-reducing procedure, said procedure comprising maintaining theswine in a closed herd, wherein all other animals in the closed herd areconfirmed to be free of at least the following pathogens: Ascarisspecies, cryptosporidium species, Echnococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, pseudorabies, Toxoplasma Gondii, staphylococcus species,Microphyton species, and Trichophyton species, porcine influenza,cytomegalovirus, arterivirus, and coronavirus, wherein the swine isisolated from contact with any non-human animals and animal housingfacilities outside of the closed herd,

harvesting a biological product from said swine, wherein said harvestingcomprises euthanizing the swine and aseptically removing the biologicalproduct from the swine,

processing said biological product comprising sterilization within 15hours of harvesting and storing said biological product in a sterilecontainer,

wherein said biological product does not contain one or moreextracellular surface glycans, wherein said product is free of Ascarisspecies, cryptosporidium species, Echnococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, pseudorabies, Toxoplasma Gondii, staphylococcus species,Microphyton species, and Trichophyton species, porcine influenza,cytomegalovirus, arterivirus, and coronavirus, and wherein said productis biologically active and comprises live cells and tissues capable ofvascularizing after xenotransplantation,

wherein cellular mitochondrial activity of said product is greater than50% as measured by MTT assay;

wherein said product is less immunogenic when transplanted into a humanxenotransplant recipient as compared to a biological product obtained axenotransplantation product made from conventional Gal-T knockout swine,from conventional triple knockout swine, from transgenic swine, fromwild-type animals, and/or allograft,

wherein said product is less antigenic when transplanted into a humanxenotransplant recipient as compared to a biological product obtainedfrom a xenotransplantation product made from conventional Gal-T knockoutswine, from conventional triple knockout swine, from transgenic swine,from wild-type animals, and/or allograft, and

wherein said product is resistant to rejection by the humanxenotransplant recipient in the absence of administration ofimmunosuppressant drugs or other immunosuppressant therapies to thehuman xenotransplant recipient.

2. The method of any item or combination of items disclosed herein,wherein the processing comprises ultraviolet (UV) sterilization within15 hours of harvesting.

3. The method of any item or combination of items disclosed herein,wherein the product is laid flat on a sterile surface and exposed to aUV lamp having a UV-C intensity of at least 100 uW/cm² for at least 2minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or 2.5 minutes, and turnedover such that its opposite surface is exposed to the UV lamp for atleast 2 minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or 2.5 minutes toobtain a UV-treated product.

4. The method of any item or combination of items disclosed herein,wherein the product is laid flat on a sterile surface and exposed to aUV-C dosage of at least 100,000 uW sec/cm² and up to 800,000, 700,000,600,000, 500,000, 400,000, 300,000 or 200,000 uW sec/cm².

5. The method of any item or combination of items disclosed herein,wherein the product is laid flat on a sterile surface and exposed to aUV-C dosage of at least 200,000 uW sec/cm² and up to 800,000, 700,000,600,000, 500,000, 400,000, or 300,000 uW sec/cm².

6. The method of any item or combination of items disclosed herein,further comprising placing the UV-treated product in apreviously-sterilized container and subsequently exposing all surfacesof the container to a UV lamp having a UV-C intensity of at least 100uW/cm² for at least 2 minutes and up to 15, 12, 10, 8, 6, 5, 4, 3, or2.5 minutes, exposing all surfaces of a previously-sterilized cap of thesterile container to the UV-lamp for at least two minutes, andsubsequently securing the cap onto the sterile container.

7. The method of any item or combination of items disclosed herein,wherein said processing step further comprises at least one of placingthe biological product into an antimicrobial solution containing one ormore of antibiotics such as placing the biological product into anantimicrobial solution containing one or more of antibiotics such asAmpicillin/Ceftazidime/Vancomycin/Amphotericin-B, flow cytometry todetermine extracellular surface glycan epitope elimination,cryopreservation using cryoprotective-media packaging.

8. The method of any item or combination of items disclosed herein,wherein said storing step further comprises cryopreserving the product,wherein the cryopreserving step comprises a controlled-rate freezingtechnique beginning at about 4° C. and lowering by about 1° C. perminute until −40° C. followed by temperature reduction to about −80° C.within 5 minutes.

9. The method of any item or combination of items disclosed herein,wherein the xenotransplantation product is confirmed to be free of oneor more extracellular surface glycan epitopes.

10. The method of any item or combination of items disclosed herein,wherein the organism is delivered by C-section.

11. The method of any item or combination of items disclosed herein,further comprising administering one or more anti-microbial agents andone or more vaccines to the organism.

12. The method of any item or combination of items disclosed herein,wherein the one or more vaccines are killed vaccines.

13. The method of any item or combination of items disclosed herein,further comprising feeding the organism sterile or purified water and agrain-based feed that does not contain animal proteins or cattle-basedmaterial.

14. The method of any item or combination of items disclosed herein,further comprising irradiation sterilizing bedding, cages, and feed forthe organism.

15. The method of any item or combination of items disclosed herein,wherein the bioburden-reducing procedure further comprises airfiltration of the closed herd, chemically sterilizing cages and vehiclesused to house or transport the organism, bathing the organism inchlorhexidine, bathing the organism in sterile saline, bathing theorganism in an anti-fungal solution, or a combination the method of anyone of items 1-15, further comprising screening said organism fordetectable levels of rickettsia, mycoplasma, transmissible spongiformencephalopathies (TSEs), and parasites before said rearing step.

16. The method of any item or combination of items disclosed herein,further comprising rearing a plurality of additional organisms in thesame manner as the organism and performing periodic necropsy, histology,and pathology on the additional organisms to confirm that the closedherd remains free of pathogens and parasites.

17. The method of any item or combination of items disclosed herein,further comprising quarantining said organism for at least two weeksbefore the harvesting step and screening the organism for detectablelevels of pathogens.

18. The method of any item or combination of items disclosed herein,where the quarantining step further comprises physical examination ofthe organism and one or more tests selected from complete blood count,peripheral blood smear, and fecal exam for parasites.

19. The method of any item or combination of items disclosed herein,wherein the organism is euthanized during the harvesting step andfurther comprising conducting a necropsy including gross,histopathological, and microbiological evaluation.

20. The method of any item or combination of items disclosed herein,further comprising collecting and cryopreserving tissue samples from atleast one of spleen, liver, bone marrow, central nervous system, andlung from the organism at necropsy.

21. The method of any item or combination of items disclosed herein,further comprising collecting plasma and/or cerebrospinal fluid from theorganism during the harvesting step.

22. The method of any item or combination of items disclosed herein,further comprising measuring at least one of cell viability in thebiological product and biologically active molecules selected fromcytokines, hormones, and neurotransmitters secreted or produced by thebiological product.

23. The method of any item or combination of items disclosed herein,further comprising cutting said product to a desired size; bathing saidcut product in an anti-pathogen bath; and storing said cut and bathedproduct at a temperature that will preserve said cut and bathed product.

24. The method of any item or combination of items disclosed herein,further comprising applying said product onto a scaffold or at least thesame size as the product, rolling said product and said scaffold,placing said rolled product and scaffold into a sterile container, andstoring the container at a temperature between about 10° C. to about−80° C.

25. A biological product for clinical xenotransplantation derived from anon-wild type, biologically engineered, swine produced according to themethod of any item or combination of items disclosed herein,

wherein a cell from the swine has been genetically modified such that itexpresses a major histocompatibility complex of a known human sequenceor a human recipient of said biological product.

26. The biological product of any item or combination of items disclosedherein, wherein said genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

27. The biological product of any item or combination of items disclosedherein, wherein said genome further comprises a disruptedβ1,4-N-acetylgalactosaminyltransferase gene.

28. The biological product of any item or combination of items disclosedherein—28, wherein said genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

29. The biological product of any item or combination of items disclosedherein, wherein the cell from the swine has a genome including ascarless exchange of one or more endogenous swine leukocyte antigenalleles with one or more human leukocyte antigen alleles.

30. The biological product of any item or combination of items disclosedherein, wherein the cell from the swine has a genome includingreplacement of 60-70 nucleotides in length in one or more endogenousswine leukocyte antigens with a corresponding human leukocyte antigennucleotide region from a known human sequence.

31. The biological product of any item or combination of items disclosedherein, wherein the one or more isotypes are DQ and DR.

32. The biological product of any item or combination of items disclosedherein, wherein the cell from the swine has been geneticallyreprogrammed at one or more of a Class I HLA, a MHCII, a B cell Fcreceptor, glycoprotein galactosyltransferase 1,3 (GGTA1), NOD-likereceptor family CARD domain containing 5 (NLRC5) and an immunoglobulin G(IgG).

33. The biological product of any item or combination of items disclosedherein, wherein cells from said genetically modified swine whenco-cultured with human peripheral blood mononuclear cells (PBMCs) inducea lower production of cytokine Interleukin 6 (IL-6) and a lower CD8+ Tcell immune response as compared to cells from said non-geneticallymodified counterpart swine, as measured by an in vitro mixed lymphocytereaction assay.

34. The biological product of any item or combination of items disclosedherein, wherein said genetically modified swine further comprisesreduced protein expression of an endogenous gene not expressed in ahuman and increased protein expression of a gene expressed in a human.

35. A combination product comprising an epidermal autograft product froma human subject and the product of any item or combination of itemsdisclosed herein.

36. A method of preparing biological product for clinicalxenotransplantation into a human comprising selecting a known humanmajor histocompatibility complex gene sequence or sequencing a humanrecipient's major histocompatibility complex gene, genetically modifyingcells of a swine to replace a portion of the swine's majorhistocompatibility complex gene sequence with a corresponding portion ofthe known human major histocompatibility complex gene sequence or acorresponding portion of the human recipient's major histocompatibilitycomplex gene sequence such that the swine's cells express thecorresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence, isolatingone or more cells, tissues, and/or organs from the swine that expressthe corresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence, wherein theisolated cells, tissues, and/or organs are the biological product.

37. The method of any item or combination of items disclosed hereinwherein the genetically modifying step comprises preparing templatemajor histocompatibility complex sequences, preparing CRISPR-Cas9plasmids, cloning template major histocompatibility complex sequencesinto the plasmids, determining CRISPR cleavage sites at the majorhistocompatibility complex locus in the swine cells, cloning gRNAsequences into one or more CRISPR-Cas9 plasmids, administeringCRISPR-Cas9 plasmids into cells of a swine, performing CRIPSR/Cas9cleavage at the major histocompatibility complex locus of the swinecells, replacing the major histocompatibility complex locus in the swinecells with one or more template major histocompatibility complexsequences matching the corresponding portion of the known human majorhistocompatibility complex gene sequence or the corresponding portion ofthe human recipient's major histocompatibility complex gene sequence.

38. The method of any item or combination of items disclosed herein,further comprising sequencing cells of the swine after performing themajor histocompatibility complex replacement steps and comparing thesequence of the swine's major histocompatibility complex genes with theknown human sequence or the human recipient's major histocompatibilitycomplex genes, and if the major histocompatibility complex sequences inthe swine cells have been successfully replaced, isolating one or morecells, tissues, and/or organs from the swine that express the knownhuman sequence or the human recipient's major histocompatibility complexto prepare the biological product.

39. The method of any item or combination of items disclosed herein,further comprising transplanting the biological product from the majorhistocompatibility complex sequence-replaced swine into the humanrecipient.

40. The method of any item or combination of items disclosed herein,further comprising breeding major histocompatibility complexsequence-replaced swine for at least one generation to obtain progenyswine, and then isolating one or more cells, tissues, and/or organs fromthe progeny swine that express the known human sequence or the humanrecipient's major histocompatibility complex, wherein the isolatedcells, tissues, and/or organs are the biological product.

41. The method of any item or combination of items disclosed herein,wherein the genome of said swine comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

42. The method of any item or combination of items disclosed herein,wherein the genome of said swine comprises a disruptedβ1,4-N-acetylgalactosaminyltransferase gene.

43. The method of any item or combination of items disclosed herein,wherein said genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

44. The method of any item or combination of items disclosed herein,wherein the cell from the swine has a genome including a scarlessexchange of one or more endogenous swine leukocyte antigen alleles withone or more human leukocyte antigen alleles.

45. The method of any item or combination of items disclosed herein,wherein the cell from the swine has a genome including replacement of60-70 nucleotides in length in one or more endogenous swine leukocyteantigens with a corresponding human leukocyte antigen nucleotide regionfrom a known human sequence.

46. The method of any item or combination of items disclosed herein,wherein the human leukocyte antigen nucleotide region from the knownhuman sequence is one or more of DQ and DR, preferably one or more ofDQ_(β) and DR_(β).

47. The method of any item or combination of items disclosed herein,wherein the cell from the swine has been genetically reprogrammed at oneor more of a Class I HLA, a MHCII, a B cell Fc receptor, glycoproteingalactosyltransferase 1,3 (GGTA1), NOD-like receptor family CARD domaincontaining 5 (NLRC5) and an immunoglobulin G (IgG).

48. The method of any item or combination of items disclosed herein,wherein cells from said genetically modified swine when co-cultured withhuman peripheral blood mononuclear cells (PBMCs) induce a lowerproduction of cytokine Interleukin 6 (IL-6) and a lower CD8+ T cellimmune response as compared to cells from said non-genetically modifiedcounterpart swine, as measured by an in vitro mixed lymphocyte reactionassay.

49. The method of any item or combination of items disclosed herein,wherein said genetically modified swine further comprises reducedprotein expression of an endogenous gene not expressed in a human andincreased protein expression of a gene expressed in a human.

50. A genetically reprogrammed swine comprising a nuclear genome havingdisrupted surface glycan(s), e.g., alpha-1,3 galactosyltransferase gene,and genetically modified such that it expresses a portion of a majorhistocompatibility complex of a known human sequence or a humanrecipient of cells, tissue, and/or an organ isolated from thegenetically reprogrammed swine and optionally further modified accordingto any item or combination of items disclosed herein.

51. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein said genetically reprogrammed swine'sgenome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

52. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein said genetically reprogrammed swine'sgenome further comprises a disruptedβ1,4-N-acetylgalactosaminyltransferase gene.

53. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, comprising a nuclear genome with at least twoSLA gene deletions and at least two HLA gene insertions fromcorresponding portions of HLA genes, wherein the HLA genes are from theknown human sequence or the human recipient, from a consensus sequencefor a given population group, or from a library sequence.

54. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein said genome further comprises adisrupted cytidine monophosphate-N-acetylneuraminic acid hydroxylase(CMAH) gene.

55. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein the cell from the swine has a genomeincluding a scarless exchange of one or more endogenous swine leukocyteantigen alleles with one or more human leukocyte antigen alleles.

56. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein the cell from the swine has a genomeincluding replacement of 60-70 nucleotides in length in one or moreendogenous swine leukocyte antigens with a corresponding human leukocyteantigen nucleotide region from a known human sequence.

57. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein the human leukocyte antigen nucleotideregion from the known human sequence is one or more of DQ and DR,preferably one or more of DQ_(β) and DR_(β).

58. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein the cell from the swine has beengenetically reprogrammed at one or more of a Class I HLA, a MHCII, a Bcell Fc receptor, glycoprotein galactosyltransferase 1,3 (GGTA1),NOD-like receptor family CARD domain containing 5 (NLRC5) and animmunoglobulin G (IgG).

59. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein cells from said genetically modifiedswine when co-cultured with human peripheral blood mononuclear cells(PBMCs) induce a lower production of cytokine Interleukin 6 (IL-6) and alower CD8+ T cell immune response as compared to cells from saidnon-genetically modified counterpart swine, as measured by an in vitromixed lymphocyte reaction assay.

60. The genetically reprogrammed swine of any item or combination ofitems disclosed herein, wherein said genetically modified swine furthercomprises reduced protein expression of an endogenous gene not expressedin a human and increased protein expression of a gene expressed in ahuman.

61. A method of preparing a genetically reprogrammed swine comprising anuclear genome having disrupted surface glycan(s), e.g., alpha-1,3galactosyltransferase gene, and genetically modified such that itexpresses a major histocompatibility complex of a known human sequenceor a human recipient of a cell, a tissue, and/or an organ isolated fromsaid genetically reprogrammed swine, the method comprising selecting aknown human major histocompatibility complex sequence or sequencing thehuman recipient's major histocompatibility complex gene, obtaining aswine comprising a nuclear genome having at least one disrupted swinesurface glycan gene, genetically modifying cells of the swine to replaceportions of the swine's major histocompatibility complex gene withcorresponding portions of the known human major histocompatibilitycomplex gene or corresponding portions of the human recipient's majorhistocompatibility complex gene such that the swine's cells expressportions of the human recipient's major histocompatibility complex.

62. The method of any item or combination of items disclosed herein,wherein said genetically reprogrammed swine's genome further comprises adisrupted gene encoding β1,4-N-acetylgalactosaminyltransferase.

63. The method of any item or combination of items disclosed herein,wherein said genetically reprogrammed swine comprises a nuclear genomewith at least two SLA gene deletions and at least two HLA geneinsertions, wherein the HLA genes are from the human recipient, from aconsensus sequence for a given population group, or from a librarysequence.

64. The method of any item or combination of items disclosed herein,wherein said genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

65. The method of any item or combination of items disclosed herein,wherein the cell from the genetically reprogrammed swine has a genomeincluding a scarless exchange of one or more endogenous swine leukocyteantigen alleles with one or more human leukocyte antigen alleles.

66. The method of any item or combination of items disclosed herein,wherein the cell from the genetically reprogrammed swine has a genomeincluding replacement of 60-70 nucleotides in length in one or moreendogenous swine leukocyte antigen nucleotide regions with acorresponding human leukocyte antigen nucleotide region from a knownhuman sequence.

67. The method of any item or combination of items disclosed herein,wherein the human leukocyte antigen nucleotide region from the knownhuman sequence is one or more of DQ and DR, preferably one or more ofDQ_(β) and DR_(β).

68. The method of any item or combination of items disclosed herein,wherein the cell from the swine has been genetically reprogrammed at oneor more of a Class I HLA, a MHCII, a B cell Fc receptor, glycoproteingalactosyltransferase 1,3 (GGTA1), NOD-like receptor family CARD domaincontaining 5 (NLRC5) and an immunoglobulin G (IgG).

69. The method of any item or combination of items disclosed herein,wherein cells from said genetically modified swine when co-cultured withhuman peripheral blood mononuclear cells (PBMCs) induce a lowerproduction of cytokine Interleukin 6 (IL-6) and a lower CD8+ T cellimmune response as compared to cells from said non-genetically modifiedcounterpart swine, as measured by an in vitro mixed lymphocyte reactionassay.

70. The method of any item or combination of items disclosed herein,wherein said genetically modified swine further comprises reducedprotein expression of an endogenous gene not expressed in a human andincreased protein expression of a gene expressed in a human.

71. A method of delaying, reducing, or preventing rejection, separation,or adverse reactions to xenotransplanted tissues in a human recipient,comprising selecting a known human major histocompatibility complex genesequence or sequencing the human recipient's major histocompatibilitycomplex gene, obtaining a swine comprising a nuclear genome havingdisrupted alpha-1,3 galactosyltransferase gene, genetically modifyingcells of the swine to replace a portion of the swine's majorhistocompatibility complex gene with a corresponding portion of theknown human major histocompatibility complex gene sequence or thecorresponding portion of the human recipient's major histocompatibilitycomplex gene sequence such that the swine's cells express thecorresponding portion of the known human major histocompatibilitycomplex gene sequence or the corresponding portion of the humanrecipient's major histocompatibility complex gene sequence, isolatingcells, tissue, and/or an organ from the genetically reprogrammed swinethat express the corresponding portion of the known human majorhistocompatibility complex gene sequence or the corresponding portion ofthe human recipient's major histocompatibility complex gene sequence,and transplanting the isolated cells, tissue, and/or an organ from thegenetically reprogrammed swine into the human recipient.

72. The method of any item or combination of items disclosed herein,wherein said genetically reprogrammed swine's genome further comprises adisrupted β1,4-N-acetylgalactosaminyltransferase gene.

73. The method of any item or combination of items disclosed herein,wherein said genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

74. The method of any item or combination of items disclosed herein,wherein the cell from the swine has a genome including a scarlessexchange of one or more endogenous swine leukocyte antigen alleles withone or more human leukocyte antigen alleles.

75. The method of any item or combination of items disclosed herein,wherein the cell from the swine has a genome including replacement of60-70 nucleotides in length in one or more endogenous swine leukocyteantigens with a corresponding human leukocyte antigen nucleotide regionfrom a known human sequence.

76. The method of any item or combination of items disclosed herein,wherein the human leukocyte antigen nucleotide region from the knownhuman sequence is one or more of DQ and DR, preferably one or more ofDQ_(β) and DR_(β).

77. The method of any item or combination of items disclosed herein,wherein the cell from the swine has been genetically reprogrammed at oneor more of a Class I HLA, a MHCII, a B cell Fc receptor, glycoproteingalactosyltransferase 1,3 (GGTA1), NOD-like receptor family CARD domaincontaining 5 (NLRC5) and an immunoglobulin G (IgG).

78. The method of any item or combination of items disclosed herein,wherein cells from said genetically modified swine when co-cultured withhuman peripheral blood mononuclear cells (PBMCs) induce a lowerproduction of cytokine Interleukin 6 (IL-6) and a lower CD8+ T cellimmune response as compared to cells from said non-genetically modifiedcounterpart swine, as measured by an in vitro mixed lymphocyte reactionassay.

79. The method of any item or combination of items disclosed herein,wherein said genetically modified swine further comprises reducedprotein expression of an endogenous gene not expressed in a human andincreased protein expression of a gene expressed in a human.

80. A biological product for clinical xenotransplantation derived from anon-wild type, biologically engineered, non-human organism,

-   -   wherein said organism from which said biological product is        derived is produced through natural breeding and/or assisted        reproductive technologies, and    -   wherein said organism has a biologically engineered genome such        that it does not express one or more extracellular surface        glycan epitopes, and    -   wherein said organism is free of at least the following        pathogens: Ascaris species, Cryptosporidium species,        Echnococcus, Strongyloids sterocolis, Toxoplasma gondii,        Brucella suis, Leptospira species, Mycoplasma hyopneumoniae,        pseudorabies, Toxoplasma gondii, Staphylococcus species,        Microphyton species, and Trichophyton species, porcine        influenza, cytomegalovirus, arterivirus, and coronavirus,    -   wherein said organism is not transgenic,    -   wherein said product does not contain one or more extracellular        surface glycans,    -   wherein said product is free of: Ascaris species,        cryptosporidium species, Echnococcus, Strongyloids sterocolis,        Toxoplasma gondii, Brucella suis, Leptospira species, Mycoplasma        hyopneumoniae, pseudorabies, Toxoplasma gondii, Staphylococcus        species, Microphyton species, and Trichophyton species, porcine        influenza, cytomegalovirus, arterivirus, and coronavirus,    -   wherein said product has not been terminally sterilized,    -   wherein said product is less immunogenic compared to biological        product obtained from a xenotransplantation product made from        conventional Gal-T knockout swine, from conventional triple        knockout swine, from transgenic swine, from wild-type animals,        and/or allograft,    -   wherein said product is less antigenic when transplanted into a        human xenotransplant recipient as compared to a biological        product obtained from a xenotransplantation product made from        conventional Gal-T knockout swine, from conventional triple        knockout swine, from transgenic swine, from wild-type animals,        and/or allograft, and    -   wherein said product is biologically active and comprises live        cells and tissues capable of vascularizing after        xenotransplantation.

81. The product of any item or combination of items disclosed herein,wherein said product is resistant to rejection by a human xenotransplantrecipient in the absence of administration of immunosuppressant drugs orother immunosuppressant therapies to the transplant recipient.

82. The product of any item or combination of items disclosed herein,wherein said product comprises an organ or tissue.

83. The product of any item or combination of items disclosed herein,wherein said organ comprises a liver, a lung, a kidney, or skin.

84. The product of any item or combination of items disclosed herein,wherein said tissue comprises a nerve.

85. The product of any item or combination of items disclosed herein,wherein said organ is capable of vascularizing in the region of thetransplant in said patient following said xenotransplantation.

86. The product of any item or combination of items disclosed herein,wherein said skin is capable of promoting collagen production in theregion of the transplant in said patient following saidxenotransplantation.

87. The product of any item or combination of items disclosed herein,wherein said organism has a genome with at least one further disruptedgene selected from the group consisting of genes encoding: cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH), β1-4N-acetylgalactosaminyltransferase, swine leukocyte antigens,alpha-1,2-fucosyltransferase, cytotoxic T lymphocyte-associated antigen,tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL),Fas ligand (Fas L), CD55, CD59, and CD46.

88. The product of any item or combination of items disclosed herein,wherein said organism has a genome with at least one furthermodification to express at least one protein selected from the groupconsisting of: human leukocyte antigens, MHC type I; MHC type II;hCD46-human membrane cofactor protein (MCP); hCTLA4-Ig-human cytotoxicT-murine lymphocyte antigen 4 fused with Ig heavy chains; hCD55-humandecay-accelerating factor (DAF); hCD59-human protectin; H-transferase;hTM-human thrombomodulin; hA20-tumor necrosisfactor-alpha-(TNF-alpha)-inducible gene; HLA-E/beta-microglobulin; humanheme oxygenase-1 (hHO-1).

89. The product of any item or combination of items disclosed herein,wherein the product is biologically active and comprises live cells andtissues capable of vascularizing after cryopreservation at a temperatureat or below −40° C. for at least one year.

90. The product of any item or combination of items disclosed herein,wherein said product is free of at least two of Ascaris species,Cryptosporidium, Echinococcus, Strongyloids sterocolis, Toxoplasmagondii, Brucella suis, Leptospira species, Mycoplasma Hyopneumoniae,Porcine Reproductive and Respiratory Syndrome Virus (PRRSV),Pseudorabies, Toxoplasma Gondii, Porcine Influenza A virus, Bordetellabronchiseptica, staphylococci, Microphyton species, Trichophytonspecies, adenovirus, arbovirus, bovine viral diarrhea virus,calicivirus, cardiovirus, circovirus 2, circovirus 1,encephalomyocarditus virus, eperytherozoon, Haemophilus suis, herpes andherpes-related viruses, iridovirus, kobuvirus, leptospirillum, Listeria,Mycobacterium TB, Mycoplasma, orthomyxovirus, papovirus, parainfluenzavirus 3, paramyxovirus, parvovirus, pasavirus-1, pestivirus,picobirnavirus (PBV), picornavirus, porcine circovirus-like virus,porcine astrovirus, porcine bacovirus, porcine bocavirus-2, porcinebocavirus-4, porcine enterovirus-9, porcine epidemic diarrhea virus(PEDV), porcine polio virus, porcine lymphotropic herpes virus (PLHV),porcine stool associated circular virus (PoSCV), posavirus-1, pox virus,rabies-related viruses, reovirus, rhabdovirus, rickettsia, sapelovirus,sapovirus, Staphylococcus hyicus, suipoxvirus, teschen, torovirus,torque teno sus virus-2 (TTSuV-2), transmissible gastroenteritus virus,vesicular stomatitis virus, and prions.

91. A method for the production of a second-generation non-wild type,biologically engineered piglet, comprising:

-   -   delivering a non-wild type, biologically engineered piglet from        a pregnant sow through Cesarean section, wherein said sow was        produced through natural breeding and/or assisted reproductive        technologies, and    -   holding said delivered piglet in an isolated closed herd wherein        all other pigs in the isolated closed herd are confirmed to be        free of at least the following pathogens: cytomegalovirus,        arterivirus, and coronavirus, and wherein said piglet is free of        at least the following pathogens: cytomegalovirus, arterivirus,        and coronavirus;    -   rearing said piglet in said isolated closed herd;    -   mating said piglet, upon sexual maturity, with another pig that        is also maintained in said isolated closed herd and free of said        pathogens; and    -   delivering a new piglet resulting from said mating, wherein said        new piglet is the second-generation non-wild type, biologically        engineered piglet that is also free of said pathogens.

92. A pig produced by the method of item 91 or any item or combinationof items disclosed herein.

93. The method of item 92 or any item or combination of items disclosedherein, which further comprises harvesting a biological product fromsaid new piglet.

94. The method of item 93 or any item or combination of items disclosedherein, wherein said product comprises an organ or tissue.

95. The method of item 94 or any item or combination of items disclosedherein, wherein said organ comprises a liver, lung, kidney, or skin.

96. The method of item 95 or any item or combination of items disclosedherein, wherein said tissue comprises a nerve.

97. The method of item 92 or any item or combination of items disclosedherein, wherein said non-wild type, biologically engineered piglet has agenome with a disrupted alpha-1,3 galactosyltransferase gene.

98. The method of any one of items 92 and 94-98 or any item orcombination of items disclosed herein, wherein said second-generationnon-wild type, biologically engineered piglet has a genome with at leastone further disrupted gene selected from the group consisting of genesencoding: cytidine monophosphate-N-acetylneuraminic acid hydroxylase(CMAH), β1-4 N-acetylgalactosaminyltransferase, swine leukocyteantigens, alpha-1,2-fucosyltransferase, cytotoxic Tlymphocyte-associated antigen, tumor necrosis factor-alpha-relatedapoptosis-inducing ligand (TRAIL), Fas ligand (Fas L), CD55, CD59, andCD46.

99. The method of any one of items 92 and 94-99 or any item orcombination of items disclosed herein, wherein said second-generationnon-wild type, biologically engineered piglet has a genome with at leastone further modification to express at least one protein selected fromthe group consisting of: human leukocyte antigens, MHC type I; MHC typeII; hCD46-human membrane cofactor protein (MCP); hCTLA4-Ig-humancytotoxic T-murine lymphocyte antigen 4 fused with Ig heavy chains;hCD55-human decay-accelerating factor (DAF); hCD59-human protectin;H-transferase; hTM-human thrombomodulin; hA20-tumor necrosisfactor-alpha-(TNF-alpha)-inducible gene; HLA-E/beta-microglobulin; humanheme oxygenase-1 (hHO-1).

100. The method of any one of items 92 and 94-100 or any item orcombination of items disclosed herein, further comprising after each ofsaid delivering steps, placing each of the non-wild type, biologicallyengineered piglet and the second-generation non-wild type, biologicallyengineered piglet in a warmed sterilization agent solution bath.

101. The method of any one of items 92 and 94-101 or any item orcombination of items disclosed herein, wherein the non-wild type,biologically engineered piglet and the second-generation non-wild type,biologically engineered piglet are maintained in a closed herd such thatthe non-wild type, biologically engineered piglet, the second-generationnon-wild type, biologically engineered piglet, and human care personnelare quarantined from contact with any pigs and pig housing facilitiesoutside of the closed herd.

102. The method of any one of items 92 and 94-102 or any item orcombination of items disclosed herein, further comprising administeringone or more anti-microbial agents and one or more vaccines to thenon-wild type, biologically engineered piglet and the second-generationnon-wild type, biologically engineered piglet.

103. The method of any one of items 92 and 94-103 or any item orcombination of items disclosed herein, further comprising irradiationsterilizing bedding and feed for the non-wild type, biologicallyengineered piglet and the second-generation non-wild type, biologicallyengineered piglet.

104. The method of any one of items 92 and 94-104 or any item orcombination of items disclosed herein, further comprising the non-wildtype, biologically engineered piglet and the second-generation non-wildtype, biologically engineered piglet with sterile or purified water anda grain-based feed that does not contain animal proteins or cattle-basedmaterial.

105. A method of treating a human subject who has suffered an injuryrequiring a skin graft, the method comprising transplanting a skin graftfrom a second-generation non-wild type, biologically engineered pigletto the subject, wherein the second-generation non-wild type,biologically engineered piglet is produced by the method of item 92 orany item or combination of items disclosed herein, wherein the skingraft is free of at least the following pathogens: cytomegalovirus,arterivirus, and coronavirus, wherein immunosuppressant drugs or otherimmunosuppressant therapies are not administered to the subject.

106. The method of item 106 or any item or combination of itemsdisclosed herein, further comprising monitoring the skin graft forclinical signs of rejection, after detection of one or more clinicalsigns of rejection of the skin graft, removing the skin graft andreplacing it with an allogeneic skin graft or an autologous skin graft.

107. The method of item 107 or any item or combination of itemsdisclosed herein, wherein the one or more clinical signs of rejectionare selected from the group consisting of lack or loss avascularization; sloughing; white color; darker or pale color comparedto normal skin; cooler temperature as compared to normal skin;granulation; crust or scab formation; discharge; and loss or lesseningof pliability.

108. The method of any one of items 106-108 or any item or combinationof items disclosed herein, wherein the injury is a partial thicknesswound or a full thickness wound.

109. The method of any one of items 106-108 or any item or combinationof items disclosed herein, wherein the injury comprises burns; avulsedskin; diabetic wounds; and/or venous stasis ulcers.

110. A method of treating a subject in need of a functioning livercomprising: obtaining a liver derived from a piglet made according toany one of items 92 and 94-105 or a swine made according to of any oneof items 37-50 or any item or combination of items disclosed herein,creating an extracorporeal circuit between said subject and said liver,such that blood from said subject is capable of flowing through saidliver and back to said subject; and permitting blood to flow from saidsubject through said extracorporeal circuit through said liver and backto said subject.

111. An undifferentiated cell for clinical xenotransplantation derivedfrom a piglet made according to of any one of items 92 and 94-105 or aswine made according to of any one of items 37-50 or any item orcombination of items disclosed herein, wherein said cell is capable ofbeing utilized in a regenerative therapy to generate an organ orbiological tissue.

112. A method for the xenotransplantation of a product into a humanpatient comprising:

obtaining the biological product of item 1; and

transplanting said product into a human recipient, wherein upon saidtransplantation, said product exhibits a clinical benefit.

113. The method of item 113 or any item or combination of itemsdisclosed herein, wherein said product comprises an organ or tissue.

114. The method of item 114 or any item or combination of itemsdisclosed herein, wherein said organ comprises a liver, lung, kidney orskin.

115. The method of item 115 or any item or combination of itemsdisclosed herein, wherein said tissue comprises a nerve.

116. The method of any one of items 113-116 or any item or combinationof items disclosed herein, wherein said transplanting step is performedin the absence of immunosuppressant drugs or other immunosuppressanttherapies.

117. The method of item 115 or any item or combination of itemsdisclosed herein, wherein the organ is skin and further comprisingdebriding the transplantation site before the transplanting step.

118. The method of item 115 or item 118 or any item or combination ofitems disclosed herein, wherein said skin vascularizes in the region ofthe transplant in said patient following said xenotransplantation.

119. The method of any one of items 115, and 118-119 or any item orcombination of items disclosed herein, wherein said skin producescollagen in the region of the transplant in said patient following saidxenotransplantation.

120. The method of any one of items 113-120 or any item or combinationof items disclosed herein, wherein said clinical benefit is enhancedabove an allograft product, wherein the clinical benefit compared to theallograft product is one or more of: decreased graft dislocation;increased graft adherence; granulation at level with surrounding tissue;less than 20% hyper-granulation; hematoma less than 20% of wound size;fibrin deposition of less than 20% of wound size; reduced bacterialinfection compared to allograft; increased hemostasis; inducedexpression of at least one of transforming growth factors (TGFs),fibroblast growth factors (FGFs), epidermal growth factor (EGF),Insulin-like Growth Factor (IGF-1), Platelet-derived Growth Factors(PDGFs), and vascular endothelial growth factors (VEGFs); increasedattraction and/or proliferation of at least one of human fibroblasts,human epidermal keratinocytes, human endothelial cells, and humanpluripotent stem cells; inhibiting at least one of MMP-1, MMP-2, MMP-3,MMP-8, and MMP-9; treating, reducing or inhibiting at least one ofhyperglycemia, neuropathy, vasculopathy, infection, fibrin cuff, and/orvenous hypertension; reduced cellulitis; reduced erythema; reducededema; reduced hyperesthesia; reduced induration; reduced tenderness;reduced itching; reduced abscesses; reduced incidence of toxic shocksyndrome; reduced colonization of toxin-1 producing S. aureus; reducedincidence of sepsis; and reduced colonization by at least one of E.coli, P. aeruginosa, Klebsiella spp., Providencia spp.,enterobacteriaceae, and C. albicans.

121. The method of any one of items 113-121 or any item or combinationof items disclosed herein, wherein said organism from which saidbiological product is derived is produced through natural breedingand/or assisted reproductive technologies.

122. The method of any one of items 113-122 or any item or combinationof items disclosed herein, wherein the non-human organism is geneticallymodified to disrupt at least one further disrupted gene selected fromthe group consisting of genes encoding: cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH), β1-4N-acetylgalactosaminyltransferase, swine leukocyte antigens,alpha-1,2-fucosyltransferase, cytotoxic T lymphocyte-associated antigen,tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL),Fas ligand (Fas L), CD55, CD59, and CD46.

123. The method of any one of items 113-123 or any item or combinationof items disclosed herein, wherein the non-human organism has a genomewith at least one further modification to express at least one proteinselected from the group consisting of: human leukocyte antigens, MHCtype I; MHC type II; hCD46-human membrane cofactor protein (MCP);hCTLA4-Ig-human cytotoxic T-murine lymphocyte antigen 4 fused with Igheavy chains; hCD55-human decay-accelerating factor (DAF); hCD59-humanprotectin; H-transferase; hTM-human thrombomodulin; hA20-tumor necrosisfactor-alpha-(TNF-alpha)-inducible gene; HLA-E/beta-microglobulin; humanheme oxygenase-1 (hHO-1).

124. The method of any one of items 113-124 or any item or combinationof items disclosed herein, wherein the clinical benefit comprisesforming an occlusive fibrin seal, reducing or preventing infection atthe transplantation site or the healing site, increasing or retainingfluids at the transplantation site or the healing site, increasing orretaining electrolytes at the transplantation site or the healing site,increasing or retaining temperature homeostasis at the transplantationsite or the healing site, reducing scarring at the transplantation siteor the healing site, reducing or eliminating sepsis, reduce or eliminateprotein losses, restoring bodily functions, or a combination thereof.

125. The method of any one of items 113-125 or any item or combinationof items disclosed herein, wherein the transplanted product is resistantto rejection by the human recipient in the absence of administration ofimmunosuppressant drugs or other immunosuppressant therapies to thehuman recipient.

126. The method of any one of items 113-126 or any item or combinationof items disclosed herein, further comprising performing one or more oftoe-blood pressure readings, pulse volume recordings, transcutaneousoxygen measurements, and skin perfusion pressure measurements, orfurther comprising treating the human recipient after said transplantingstep with compression therapy, vacuum assisted closure (VAC),offloading, negative pressure, hyperbaric oxygen therapy, or acombination thereof. 127. A method of producing a biological product forxenotransplantation into a human recipient, said biological productcomprising live cells and tissues that vascularize afterxenotransplantation,

the method comprising:

-   -   A) producing a non-wild type, biologically engineered swine,        wherein said swine has a biologically engineered genome such        that it does not express one or more extracellular surface        glycan epitopes,    -   B) confirming that said swine is free of at least the following        zoonotic pathogens:    -   (i) Ascaris species, cryptosporidium species, Echinococcus,        Strongyloids sterocolis, and Toxoplasma gondii in fecal matter;    -   (ii) Leptospira species, Mycoplasma hyopneumoniae, porcine        reproductive and respiratory syndrome virus (PRRSV),        pseudorabies, transmissible gastroenteritis virus (TGE)/Procine        Respiratory Coronavirus, and Toxoplasma gondii by determining        antibody titers;    -   (iii) Porcine Influenza;    -   (iv) the following bacterial pathogens as determined by        bacterial culture: Bordetella bronchisceptica,        Coagulase-positive staphylococci, Coagulase-negative        staphylococci, Livestock-associated methicillin resistant        Staphylococcus aureus (LA MRSA), Microphyton and Trichophyton        spp.;    -   (v) Porcine cytomegalovirus; and    -   (vi) Brucella suis;    -   C) maintaining the swine according to a bioburden-reducing        procedure, said procedure comprising maintaining the swine in an        isolated closed herd, wherein all other animals in the isolated        closed herd are confirmed to be free of said zoonotic pathogens,        wherein the swine is isolated from contact with any non-human        animals and animal housing facilities outside of the isolated        closed herd;    -   D) harvesting a biological product from said swine, wherein said        harvesting comprises euthanizing the swine and aseptically        removing the biological product from the swine;    -   E) processing said biological product comprising sterilization        after harvesting using a sterilization process that does not        reduce cell viability to less than 50% cell viability as        determined by a        3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide        (MTT)-reduction assay; and    -   F) storing said biological product in a sterile container under        storage conditions that preserve cell viability.

128. The method of item 127 or any item or combination of itemsdisclosed herein, which does not include terminally sterilizing thebiological product, wherein said biological product is free of Ascarisspecies, cryptosporidium species, Echinococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, porcine reproductive and respiratory syndrome,pseudorabies, staphylococcus species, Microphyton species, Trichophytonspecies, porcine influenza, porcine cytomegalovirus, arterivirus,coronavirus, Bordetella bronchiseptica, and Livestock-associatedmethicillin-resistant Staphylococcus aureus.

129. The method of item 127 or item 128 or any item or combination ofitems disclosed herein, wherein before step F), the method furthercomprises testing said processed biological product via:

-   -   a. conducting a sterility assay and confirming that aerobic and        anaerobic bacteria do not grow in the sterility assay    -   b. conducting a mycoplasma assay and confirming that mycoplasma        colonies do not grow in the mycoplasma assay,    -   c. conducting an endotoxin assay and confirming that the        biological product is free of endotoxins in the endotoxin assay,    -   d. conducting the MTT-reduction assay and confirming that the        product has at least 50% cell viability in the MTT-reduction        assay,    -   e. conducting flow cytometry and confirming that the product        does not have galactosyl-a-1,3-galactose epitopes as determined        by the flow cytometry,    -   f. conducting pathogen-detection assays specific for 18 to 35        pathogens and confirming that the product is free of Ascaris        species, cryptosporidium species, Echinococcus, Strongyloids        sterocolis, Toxoplasma gondii, Brucella suis, Leptospira        species, Mycoplasma hyopneumoniae, porcine reproductive and        respiratory syndrome, pseudorabies, Staphylococcus species,        Microphyton species, Trichophyton species, porcine influenza,        porcine cytomegalovirus, arterivirus, coronavirus, Bordetella        bronchiseptica, and Livestock-associated methicillin-resistant        Staphylococcus aureus.

130. The method of any one or combination of items 127-129 or any itemor combination of items disclosed herein, wherein the biological productis free of two or more types of extracellular surface glycan epitopes asconfirmed by flow cytometry.

131. The method of any one or combination of items 127-130 or any itemor combination of items disclosed herein, wherein the biological productis free of alpha-1,3-galactosyltransferase epitopes andN-glycolylneuraminic acid epitopes as confirmed by flow cytometry.

132. The method of any one or combination of items 127-131 or any itemor combination of items disclosed herein, wherein the biological productis free of alpha-1,3-galactosyltransferase epitopes,N-glycolylneuraminic acid epitopes, andβ1,4-N-acetylgalactosaminyltransferase epitopes as confirmed by flowcytometry.

133. The method of any one or combination of items 127-132 or any itemor combination of items disclosed herein, wherein said swine is producedthrough natural intercourse by parent swine also maintained in theisolated closed herd and also free of the following pathogens: Ascarisspecies, cryptosporidium species, Echinococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, porcine reproductive and respiratory syndrome,pseudorabies, staphylococcus species, Microphyton species, Trichophytonspecies, porcine influenza, porcine cytomegalovirus, arterivirus,coronavirus, Bordetella bronchiseptica, and Livestock-associatedmethicillin-resistant Staphylococcus aureus, and wherein said swine isbirthed through live vaginal birth.

134. The method of any one or combination of items 127-133 or any itemor combination of items disclosed herein, wherein following said livevaginal birth said swine is hand reared by one or more humans.

135. The method of any one or combination of items 127-134 or any itemor combination of items disclosed herein, further comprising rearing aplurality of additional swine in the same manner as the swine andperforming periodic necropsy, histology, and pathology on the additionalswine to confirm that the closed herd remains free of Ascaris species,cryptosporidium species, Echinococcus, Strongyloids sterocolis,Toxoplasma gondii, Brucella suis, Leptospira species, mycoplasmahyopneumoniae, porcine reproductive and respiratory syndrome,pseudorabies, Staphylococcus species, Microphyton species, Trichophytonspecies, porcine influenza, porcine cytomegalovirus, arterivirus,coronavirus, Bordetella bronchiseptica, and Livestock-associatedmethicillin-resistant Staphylococcus aureus.

136. The method of any one or combination of items 127-135 or any itemor combination of items disclosed herein, further comprising feeding theswine sterile or purified water and a grain-based feed that does notcontain animal proteins or cattle-based material and irradiationsterilizing bedding, cages, and feed for the swine.

137. The method of any one or combination of items 127-136 or any itemor combination of items disclosed herein, further comprising conductinga necropsy including gross, histopathological, and microbiologicalevaluation after the harvesting step and collecting and cryopreservingtissue samples from at least one of spleen, liver, bone marrow, centralnervous system, and lung from the swine at necropsy.

138. The method of any one or combination of items 127-137 or any itemor combination of items disclosed herein, wherein said biologicallyengineered genome further comprises a disrupted cytidinemonophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene.

139. The method of any one or combination of items 127-138 or any itemor combination of items disclosed herein, wherein said biologicallyengineered genome further comprises a disruptedβ1,4-N-acetylgalactosaminyltransferase gene.

140. The method of any one or combination of items 127-139 or any itemor combination of items disclosed herein, wherein said biologicallyengineered genome further comprises scarless exchange of one or moreendogenous swine leukocyte antigen alleles with one or more humanleukocyte antigen alleles.

141. The method of any one or combination of items 127-140 or any itemor combination of items disclosed herein, wherein said biologicallyengineered genome further comprises replacement of 50-70 nucleotides inlength in one or more endogenous swine leukocyte antigens with acorresponding human leukocyte antigen nucleotide region.

142. The method of any one or combination of items 127-141 or any itemor combination of items disclosed herein, wherein the correspondinghuman leukocyte antigen nucleotide region is DQ_(β), in combination withHLA-E, HLA-G, or both HLA-E and HLA-G.

143. The method of any one or combination of items 127-142 or any itemor combination of items disclosed herein, wherein the biologicallyengineered genome has been genetically reprogrammed at one or more of aClass I human leukocyte antigen (HLA), a major histocompatibilitycomplex (MHC) II, a B cell Fc receptor, glycoproteingalactosyltransferase 1,3 (GGTA1), NOD-like receptor family CARD domaincontaining 5 (NLRC5) and an immunoglobulin G (IgG).

144. The method of any one or combination of items 127-143 or any itemor combination of items disclosed herein, wherein the biological productwhen co-cultured with human peripheral blood mononuclear cells (PBMCs)induces a lower production of cytokine Interleukin 6 (IL-6) and a lowerCD8+ T cell immune response as compared to cells from saidnon-genetically modified counterpart swine, as measured by an in vitromixed lymphocyte reaction assay.

145. The method of any one or combination of items 127-144 or any itemor combination of items disclosed herein, wherein the biologicallyengineered genome comprises a nuclear genome with swine leukocyteantigen (SLA) deletions and HLA insertions, wherein the HLA genes arefrom the human recipient, from a consensus sequence for a givenpopulation group, or from a library sequence.

146. The method of any one or combination of items 127-145 or any itemor combination of items disclosed herein, further comprisingbiologically reprogramming the swine's genome by preparing templatemajor histocompatibility complex sequences, preparing CRISPR-Cas9plasmids, cloning template major histocompatibility complex sequencesinto the plasmids, determining CRISPR cleavage sites at the majorhistocompatibility complex locus in the swine cells, cloning gRNAsequences into one or more CRISPR-Cas9 plasmids, administeringCRISPR-Cas9 plasmids into cells of the swine, performing CRIPSR/Cas9cleavage at the major histocompatibility complex locus of the swinecells, replacing the major histocompatibility complex locus in the swinecells with one or more template major histocompatibility complexsequences from a human template major histocompatibility complexsequence.

147. The method of any one or combination of items 127-146 or any itemor combination of items disclosed herein, further comprising, prior tostep A),

-   -   a. obtaining a candidate swine group from more than one swine        from outside of the closed herd accompanied with a health        record, pedigree, and genetic test results, and housing the more        than one swine from outside of the closed herd in a quarantine        intake area for at least 7 days, and wherein swine in the        candidate swine group are non-wild type, biologically engineered        swine having biologically engineered genomes such that they do        not express one or more extracellular surface glycan epitopes,    -   b. screening the more than one swine from outside of the closed        herd for infections to identify any swine that should be removed        from the candidate swine group,    -   c. removing any identified swine from the candidate swine group        to form a screened candidate swine group,    -   d. moving the screened candidate swine group to a holding area        held wherein the swine is isolated from contact with any        non-human animals and animal housing facilities outside of the        holding area,    -   e. mating the screened candidate swine in the holding area,    -   f. delivering a non-wild type, biologically engineered piglet        from a pregnant sow through Cesarean section, wherein said sow        was produced through natural breeding and/or assisted        reproductive technologies, and    -   g. holding said delivered piglet in an isolated closed herd        wherein all other pigs in the isolated closed herd are confirmed        to be free of at least the following pathogens: cytomegalovirus,        arterivirus, and coronavirus, and wherein said piglet is free of        at least the following pathogens: Ascaris species,        Cryptosporidium species, Echinococcus, Strongyloids sterocolis,        Toxoplasma gondii, Brucella suis, Leptospira species, Mycoplasma        hyopneumoniae, porcine reproductive and respiratory syndrome,        pseudorabies, Staphylococcus species, Microphyton species,        Trichophyton species, porcine influenza, porcine        cytomegalovirus, arterivirus, coronavirus, Bordetella        bronchiseptica, and Livestock-associated methicillin-resistant        Staphylococcus aureus, and then performing step A) of item 127.

148. The method of any one or combination of items 127-147 or any itemor combination of items disclosed herein, wherein said piglet has agenome comprising a disrupted: (i) alpha-1,3 galactosyltransferase gene;(ii) cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH)gene; (iii) β1,4-N-acetylgalactosaminyltransferase gene; (i) and (ii);(i) and (iii); or (i), (ii), and (iii).

149. The method of any one or combination of items 127-148 or any itemor combination of items disclosed herein, wherein said sterilizationprocess does not include terminally sterilizing the biological product,and wherein said sterilization process comprises at least one ofexposing the harvested biological product to UV-C radiation and bathingthe harvested biological product in an anti-pathogen bath.

150. A method for the xenotransplantation of a product into axenotransplant recipient comprising:

obtaining the biological product produced by the method of any precedingitem;transplanting said biological product into a xenotransplant recipient;monitoring said recipient for at least one of:

-   -   a. vascularization of the biological product;    -   b. rejection of the biological product;    -   c. increase in an immunogenic biomarker; and    -   wherein upon said transplantation, said biological product        exhibits a clinical benefit in the xenotransplant recipient.

151. The method of item 150 or any item or combination of itemsdisclosed herein, wherein said transplanting step is performed in theabsence of immunosuppressants.

152. The method of item 150 or item 151 or any item or combination ofitems disclosed herein, wherein said clinical benefit is enhanced abovean allograft product, wherein the clinical benefit compared to theallograft product is one or more of: decreased graft dislocation;increased graft adherence; granulation at level with surrounding tissue;less than 20% hyper-granulation; hematoma less than 20% of wound size;fibrin deposition of less than 20% of wound size; reduced bacterialinfection compared to allograft; increased hemostasis; inducedexpression of at least one of transforming growth factors (TGFs),fibroblast growth factors (FGFs), epidermal growth factor (EGF),Insulin-like Growth Factor (IGF-1), Platelet-derived Growth Factors(PDGFs), and vascular endothelial growth factors (VEGFs); increasedattraction and/or proliferation of at least one of human fibroblasts,human epidermal keratinocytes, human endothelial cells, and humanpluripotent stem cells; inhibiting at least one of MMP-1, MMP-2, MMP-3,MMP-8, and MMP-9; treating, reducing or inhibiting at least one ofhyperglycemia, neuropathy, vasculopathy, infection, fibrin cuff, and/orvenous hypertension; reduced cellulitis; reduced erythema; reducededema; reduced hyperesthesia; reduced induration; reduced tenderness;reduced itching; reduced abscesses; reduced incidence of toxic shocksyndrome; reduced colonization of toxin-1 producing S. aureus; reducedincidence of sepsis; and reduced colonization by at least one of E.coli, P. aeruginosa, Klebsiella spp., Providencia spp.,enterobacteriaceae, and C. albicans.

153. The method of any one or combination of items 150-152 or any itemor combination of items disclosed herein, wherein, after thetransplanting step, the xenotransplant recipient has serum IgM and IgGlevels of 1,000 to 20,000 μg/ml.

154. The method of any one or combination of items 150-153 or any itemor combination of items disclosed herein, wherein, after thetransplanting step, the xenotransplant recipient has a serum IgM levelof 1,000 to 5,000 μg/ml.

155. The method of any one or combination of items 150-154 or any itemor combination of items disclosed herein, wherein, after thetransplanting step, the xenotransplant recipient has a serum IgG levelof 8,000 to 15,000 μg/ml.

156. The method of any one or combination of items 150-155 or any itemor combination of items disclosed herein, wherein, after thetransplanting step, the xenotransplant recipient has serum IgM and IgGlevels below serum IgM and IgG levels measured prior to transplantationor less than 10% higher than serum IgM and IgG levels measured prior totransplantation.

157. The method of any one or combination of items 150-156 or any itemor combination of items disclosed herein, wherein, after thetransplanting step, the xenotransplant recipient has a serum IgM level20% to 50% lower than the xenotransplant recipient's serum IgM levelmeasured prior to transplantation.

158. The method or product of any preceding item, wherein said producthas at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or99% mitochondrial activity.

159. The method or product of any preceding item, wherein said producthas at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85% cell viability ina 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)-reduction assay.

160. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding sugar surface glycans and MHC I are knocked out.

161. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DP, DQ, and DR_(α) are knocked out.

162. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DP, DQ, and DR_(α) are knocked out and DR_(β) isreplaced with a human DR_(β) gene sequence.

163. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DQ, DR, and DP_(α) are knocked out.

164. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DQ, DR, and DP_(α) are knocked out and DP_(β) isreplaced with a human DP_(β)αgene sequence.

165. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DR, DP, and DQ_(α) are knocked out.

166. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class II DR, DP, and DQ_(α) are knocked out and DQ_(β) isreplaced with a human DQ_(β) gene sequence.

167. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out and genes encoding MHC Class IIDQ_(α) and DQ_(β) are knocked out and DR_(α) and DR_(β) are replacedwith human DR_(α) and DR_(β) gene sequences.

168. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out and genes encoding MHC Class IIDR_(α) and DR_(β) are knocked out and DQ_(α) and DQ_(β) are replacedwith human DQ_(α) and DQ_(β) gene sequences.

169. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, a gene encoding HLA-A isknocked-in, and genes encoding MHC Class II DQ_(α) and DQ_(β) areknocked out and DR_(α) and DR_(β) are replaced with human DR_(α) andDR_(β) gene sequences.

170. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, a gene encoding HLA-A isknocked-in, and genes encoding MHC Class II DR_(α) and DR_(β) areknocked out and DQ_(α) and DQ_(β) are replaced with human DQ_(α) andDQ_(β) gene sequences.

171. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, a gene encoding HLA-B isknocked-in, and genes encoding MHC Class II DQ_(α) and DQ_(β) areknocked out and DR_(α) and DR_(β) are replaced with human DR_(α) andDR_(β) gene sequences.

172. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, a gene encoding HLA-B isknocked-in, and genes encoding MHC Class II DR_(α) and DR_(β) areknocked out and DQ_(α) and DQ_(β) are replaced with human DQ_(α) andDQ_(β) gene sequences.

173. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, genes encoding HLA-A and HLA-B areknocked-in, and genes encoding MHC Class II DQ_(α) and DQ_(β) areknocked out and DR_(α) and DR_(β) are replaced with human DR_(α) andDR_(β) gene sequences.

174. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, genes encoding HLA-A and HLA-B areknocked-in, and genes encoding MHC Class II DR_(α) and DR_(β) areknocked out and DQ_(α) and DQ_(β) are replaced with human DQ_(α) andDQ_(β) gene sequences.

175. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out and a gene encoding HLA-A isknocked-in.

176. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out and a gene encoding HLA-B isknocked-in.

177. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out and a gene encoding HLA-C isknocked-in.

178. The method, product, or swine of any preceding item, wherein thedonor animal, e.g., swine, has a modified genome such that genesencoding MHC Class I are knocked out, genes encoding HLA-A, HLA-B andHLA-C are knocked-in, and genes encoding MHC Class II DR_(α) and DR_(β)are replaced with human DR_(α) and DR_(β) gene sequences and MHC ClassII DQ_(α) and DQ_(β) are replaced with human DQ_(α) and DQ_(β) genesequences.

179. The method, product, or swine of any preceding item, wherein thedonor swine has a modified genome to knock-out: swine genescorresponding to HLA-A, HLA-B, HLA-C, and DR, and to knock-in: HLA-C;HLA-E; and HLA-G.

180. The method, product, or swine of any preceding item, wherein thedonor swine has a modified genome to knock-out: swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and toknock-in: HLA-C, HLA-E, HLA-G.

181. The method, product, or swine of any preceding item, wherein thedonor swine has a modified genome to knock-out: swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and toknock-in: HLA-C, HLA-E, HLA-G, HLA-F, and DQ.

182. The method, product, or swine of any preceding item, wherein thedonor swine has a modified genome to knock-out: SLA-11; SLA-6,7,8;SLA-MIC2; and SLA-DQA; SLA-DQB1; SLA-DQB2, and to knock-in: HLA-C;HLA-E; HLA-G; and HLA-DQ.

183. The method, product, or swine of any preceding item, wherein thereprogramming is performed using a RNA-guided clustered regularlyinterspersed short palindromic repeats (CRISPR)/CRISPR-associated (Cas)(CRISPR/Cas) nuclease system, a CRISPR/Cas dual nickase system, a zincfinger nuclease (ZFN), a transcription activator-like effector nuclease(TALEN), a meganuclease, a fusion protein comprising a programmable DNAbinding domain linked to a nuclease domain (i.e., generates adouble-stranded DNA break), and combinations thereof.

184. The method or product of any preceding item, wherein the biologicalproduct has an antigenic profile and an immunogenic profile such that itis resistant to rejection by the human recipient's immune system in theabsence of administration of immunosuppressant drugs to the humanrecipient.

The present invention is described in further detail in the followingexamples which are provided to be illustrative only, and are notintended to limit the scope of the invention.

Example 1 DPF Closed Colony Skin Graft (Monkey Studies)

It has been discovered that skin grafts derived from a DPF ClosedColony, α-1,3-galactosyltransferase [Gal-T] knockout pigs produced inaccordance with the present invention exhibit significantly longerrejection times than skin grafts derived fromα-1,3-galactosyltransferase [Gal-T] knockout pigs but that were notderived from DPF Closed Colony pigs.

Numerous prior studies evaluating rejection time ofα-1,3-galactosyltransferase [Gal-T] knockout pigs (not derived from aDPF Closed Colony) on monkeys show rejection times in the range of 11-13days. See, e.g., Albritton et al., Lack of Cross-Sensitization Betweenalpha-1,3-Galactosyltransferase Knockout Porcine and Allogeneic SkinGrafts Permits Serial Grafting, Transplantation & Volume 97, Number 12,Jun. 27, 2014, (Gal-T-KO skin grafts on recipient baboons fully rejectedby 12 or 13 days); Barone et al., “Genetically modified porcinesplit-thickness skin grafts as an alternative to allograft for provisionof temporary wound coverage: preliminary characterization,” Burns 41(2015) 565-574 (Gal-T-KO skin grafts on recipient baboons fully rejectedby 11 days); and Weiner et al., Prolonged survival of Gal-T-KO swineskin on baboons, Xenotransplantation, 2010, 17(2): 147-152 (Gal-T-KOxenogeneic split-thickness skin grafts on baboons fully rejected by 11days).

The subject invention has been shown in nonclinical studies to performon par and surprisingly better than its allograft comparators, withoutthe inherent disadvantage of inconsistent quality and unreliable andlimited availability. That is, surprisingly, at least Study No. 1 showsskin grafts derived from a DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention performed better than allograft.

Two recent studies (Study No. 1 and Study No. 2 set out below) byapplicant demonstrate that skin grafts derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention on monkeys show significantly higherrejection times, in Study 2 longer than 30 days. The geneticallyengineered source animals in this example did not contain any foreign,introduced DNA into the genome; the gene modification employed wasexclusively a knock-out of a single gene that was responsible forencoding for an enzyme that causes ubiquitous expression of acell-surface antigen. The xenotransplantation product in this exampledoes not incorporate transgene technologies, such as CD-46 or CD-55transgenic constructs.

Study No. 1

This study evaluated DPF Closed Colony, α-1,3-galactosyltransferase[Gal-T] knockout porcine xenotransplantation product material comparedto allografts as temporary wound grafts prior to autograft placement incynomolgus monkeys (Macaca fascicularis) in an experimental model offull thickness skin lesions.

Primary end points included screening for porcine endogenous retrovirus(PERV) in the grafts and the recipient as well as evaluation of thexenotransplantation product and allograft rejection and their potentialeffects on ultimate autograft take. Secondary end points includedmicrobiologic and histopathologic analysis of kidney, spleen, liver,lung, grafts, and wound bed tissues collected at necropsy.

Four (4) cynomolgus monkeys were enrolled in this study. Four (4), fullthickness wound beds measuring approximately 2-3 cm×2-3 cm were createdon the dorsal region of each animal on Day 0.

Initially, wounds were treated with either Xenogeneic skin(xenotransplantation product), a split-thickness Gal-T-transgenicporcine xenotransplantation product material, or Allogenic skin(allograft), a split-thickness allograft material, on Day 0.

On Day 15 of the study, the xenotransplantation product and allograftswere removed and replaced with split-thickness autologous skin grafts(autografts), after which the animals were survived to Day 22 of study(with the exception of moribund sacrifice Animals 1001 and 1004).

Microscopic evaluation of full thickness wound beds in a cynomolgusmonkey model treated with xenotransplantation product or allograft andremoved on Day 12 or 15 (FIG. 9A) and survived up to Day 22 (FIG. 9B)demonstrated no evidence of acute tissue rejection with either thexenotransplantation product or allograft comparable to slightly betterperformance overall with the xenotransplantation product test articlewhen compared to the allograft test article, and average to goodautograft performance following pretreatment with eitherxenotransplantation product or allograft test articles. The significantsurvival times of the xenotransplantation product prompted a follow-onstudy (Study No. 2).

Study No. 2

The objective of this study was to evaluate the safety andimmunogenicity of DPF Closed Colony, α-1,3-galactosyltransferase [Gal-T]knockout porcine xenotransplantation product material in cynomolgusmonkeys (Macaca fascicularis).

Primary end points included screening for porcine endogenous retrovirus(PERV) pre- and post-graft placement and evaluation of thexenotransplantation product rejection.

Four (4) cynomolgus monkeys were enrolled in this study. Two (2) 9 cm²full thickness wound beds were created on the dorsal region of eachanimal created on Day 0.

Wounds were treated with split-thickness Gal-T-knockout porcinexenograft material consisting of dermal and epidermal tissue layers.

In some aspects, transgenic animals may be used in accordance with thepresent disclosure. FIG. 8 shows the longitudinal progression of porcinesplit-thickness skin graft used as a temporary wound closure intreatment of full-thickness wound defects in a non-human primaterecipient. Left: POD-0, xenograft at Wound Site 2. Right: POD-30, samexenograft at Wound Site 2. FIG. 10 shows POD-30 histological images for:Top, Center: H&E, Low power image of wound site depicts completeepithelial coverage. Dotted line surrounds the residual xenografttissue. Bottom, Left: H&E, Higher power image of the large inset box. Tothe right and below the dotted line is the dermal component of thexenograft, with the xenograft dermal matrix indicated by an open arrow.To the left of the dotted line is the host dermis (black arrow) and thehost dermal matrix. Mild inflammation is present and interpreted to bein response to the xenograft test article. Bottom, Right: H&E, higherpower image of the small inset box. The dotted line roughly demonstratesthe junction between the xenograft test article (below dotted line) andnew collagen tissue (above dotted line), with intact epithelium at thetop of the image. Mild inflammation in response to the xenograft (openarrows) is observed.

FIG. 11A graphs the total serum IgM ELISA (μg/mL) for all four subjects(2001, 2002, 2101, 2102) during the course of the study. FIG. 11B graphsthe total serum IgG ELISA (μg/mL) for all four subjects (2001, 2002,2101, 2102) during the course of the study. In some aspects, subjectstransplanted with the product of the present disclosure will have serumIgM and IgG levels of less than 20,000 μg/ml each. In some aspects,subjects transplanted with the product of the present disclosure willhave serum IgM and/or IgG levels below or less than 10%, 5%, 3%, or 1%higher than serum IgM and IgG levels measured prior to transplantation.In some aspects, the claimed method may demonstrate an immunoreactivityincidence rate of less than 5%, 3%, or 1% of subjects transplanted withthe product of the present disclosure.

FIG. 12A graphs systemic concentrations of soluble CD40L as measured byLuminex 23-plex at POD-0, POD-7, POD-14, POD-21, and POD-30. FIG. 12Bgraphs systemic concentrations of TGF-alpha as measured by Luminex23-plex at POD-0, POD-7, POD-14, POD-21, and POD-30. FIG. 12C graphssystemic concentrations of IL-12/23 (p40) as measured by Luminex 23-plexat POD-0, POD-7, POD-14, POD-21, and POD-30.

Animals were terminated at 30 or 31 Days, wound sites were collected andfixed in 10% neutral buffered formalin (NBF) or Modified Davidson'sSolution for the testis and epididymis. It should be noted that whilethe animals were terminated at 30 or 31 days due to the study design andfor comparison purposes, the xenotransplantation product of the presentdisclosure is capable of resisting rejection for longer than the studyperiod used in this example.

Microscopic evaluation of full thickness wound beds in a cynomolgusmonkey model treated with xenograft and terminated on Day 30 or 31demonstrated good filling of the wound defect with host and xenografttissue.

Screening for porcine endogenous retroviruses (PERV) and porcinecytomegalovirus (PCMV) was performed separately at specifiedpost-operative intervals via specialized (porcine specific) polymerasechain reaction (PCR) and reverse transcriptase PCR (RT-PCR) testing ofsamples. The porcine xenografts, lysed PBMCS of the recipient, recipientwound bed, and highly perfused organs from the recipients at necropsywere evaluated for presence of porcine cell migration. All tests wereperformed in triplicate with internal controls for DNA and RNA, as wellas assay performance. Microbiologic (bacterial, fungal, viral) assaysand histopathologic analysis of kidney, spleen, liver, lung, xenografts,allografts, wound bed tissues collected at necropsy, and analysis ofperipheral blood were performed to test for xenograft-relatedimmunogenic biomarkers. DNA PCR was performed to test for porcine cellmigration in PBMCs from the cynomolgus monkey model treated with theproduct of the present disclosure for the following samples: (A.) (3)full-thickness (xenograft) wound beds, (B) (3) full-thickness(allograft) wound beds; (C) (2) spleen samples; and (D)(2) kidneysamples. There was no evidence of cell migration or zoonotictransmission systemically to the host. The presence of PERV isattributed to the residual pig cells in the wound bed, as verified withporcine MHC controls. Our results suggest that porcine DNA and cells didnot migrate into the circulation of the graft recipients from thegrafts, and likewise PERV or PERV-infected porcine cells did not migratepast the wound bed.

The following Table 5 shows the analysis for porcine cell migration andtransmission:

TABLE 5 MHC CCR5 Item No. PSK17-01 Sample Analysis PCMV PERV (swine)(Control) PBMC @ End-of-Study Subject # (EoS Date) 1 NHP-1001 (POD-IS) * * * * 2 NHP-1002 (POD-22) Neg (−) Neg (−) Neg (−) Pos (+) 3NHP-1003 (POD-22) Neg (−) Neg (−) Neg (−) Pos (+) 4 NHP-1004 (POD-12)Neg (−) Neg (−) Neg (−) Pos (+) Wound Bed @ End-of-Study Subject # (TestArticle) (EoS Date) 5 NHP-1001 (Xenograft) (POD- IS) * * * * 6 NHP-1001(Allograft) (POD-I S) * * * * 7 NHP-1002 (Xenograft) (POD-22) Neg (−)Neg (−) Neg (−) Pos (+) 8 NHP-1002 (Allograft) (POD-22) Neg (−) Neg (−)Neg (−) Pos (+) 9 NHP-1003 (Xenograft) (POD - 22) Neg (−) Neg (−) Neg(−) Pos (+) 10 NHP-1003 (Allograft) (POD-22) Neg (−) Neg (−) Neg (−) Pos(+) 11 NHP-1004 (Xenograft) (POD-12) Neg (−) Pos (+)^((A)) Neg (−) Pos(+) 12 NHP-1004 (Allograft) (POD-12) Neg (−) Neg (−) Neg (−) Pos (+)Spleen @ End-of-Study 13 NHP-1001 Neg (−) Neg (−) Neg (−) Pos (+) 14NHP-1004 Neg (−) Neg (−) Neg (−) Pos (+) Kidney @ End-of-Study 15NHP-1001 Neg (−) Neg (−) Neg (−) Pos (+) 16 NHP-1004 Neg (−) Neg (−) Neg(−) Pos (+) Key for Table 5: Neg (−) = Negative Pos (+) = Positive * =Test Not Performed or Sample Not Acceptable, due to unrelated, studydesign-related logistical or preservation issue Pos (+)^((A)) The woundbed for NHP 1004 (PERV positive) underwent co-culture studies toascertain whether the detected virus present at the interface betweengraft and recipient (host) could infect permissive human cells.Co-culture of the xenograft and recipient wound bed cells withpermissive human cells for PERV infection and replication did notdemonstrate productive infection in the target cells (HEK293), after a23-day culture.

Example 2

The following example provides a description of a process of harvestingand processing skin from a designated pathogen freeα-1,3-galactosyltransferase [Gal-T] knockout swine produced inaccordance with the present invention, with the skin to be used as axenogeneic skin product for human transplantation. In some of theseaspects, the xenotransplantation product consists of split thicknessgrafts consisting of dermal and epidermal tissue layers containingvital, non-terminally sterilized porcine cells derived from specialized,genetically engineered, Designated Pathogen Free (DPF), source animals(alpha 1,3 galactosyltransferase knockout [Gal-T-KO] miniature swine).

The genetically engineered source animals in this example do not containany foreign, introduced DNA into the genome; the gene modificationemployed is exclusively a knock-out of a single gene that wasresponsible for encoding for an enzyme that causes ubiquitous expressionof a cell-surface antigen. The xenotransplantation product in thisexample does not incorporate transgene technologies, such as CD-46 orCD-55 transgenic constructs.

The process and techniques disclosed herein are but examples, and do notlimit the scope of the invention. It will be fully understood that whilethis example is directed to xenotransplantation skin products, severalof the steps in the following process and aspects of the overallapproach can be applied to other organs or tissues, including, but notlimited to, kidney, lung, liver, pancreas, nerve, heart, intestine, andother organs or tissue. It will be further understood that modificationsto the processes and methods disclosed in this example (includingadditions or omissions of one or more process or method steps) can bemade in relation to the harvesting and processing of other organs ortissue besides skin. This understanding is based in part on the factthat other organs and tissue will have different physicalcharacteristics and so harvesting and processing steps for such otherorgans or tissue will be different from this example in certainpractical ways (e.g., a kidney, heart, liver, lung, or other whole organwill not be cut to size and packaged in a cryovial supported by nylonmesh). Nonetheless, it will be further understood that additions oromissions of one or more process or method steps as applied to each suchorgan or tissue may be made to this example utilizing approaches knownin the art (e.g., a harvested kidney, heart, liver, lung, or other wholeorgan will, in some aspects, be placed in an antipathogen bath orexposed to UV light as described herein for the removal of pathogensfollowing harvest, and placed in one or more closure systems. Forexample, such one or more closure systems could include, but not belimited to, a first closure system (e.g., utilizing an inert materialfor initial closure to surround the organ to prevent the organ fromcoming into contact with or adhering to other materials proximate to theorgan) and/or a second closure system (e.g., a sterile and secure outercontainer that contains the organ and first closure system (if a firstclosure system is utilized)). Such organs within such closure system(s)are configured to be transported to a clinical site as whole organs,stored, protected and transported in temperatures, sterility, and otherconditions to maintain sterility and cell viability for transplantationas described herein at the clinical site.

Animal Preparation

Skin product processing occurs in a single, continuous, andself-contained, segregated manufacturing event that begins with thesacrifice of the source animal through completion of the production ofthe final product.

Xenogeneic skin grafts derived from the DPF Closed Colony is received,with the swine being recently euthanized via captive bolt euthanasia inanother section of the DPF Isolation Area. The source animal iscontained in a sterile, non-porous bag that is contained within aplastic container which is delivered into the DPF Isolation Area andplaced in an operating room where the procedure to harvest skin from thesource animal will occur. All members of the operating team should be infull sterile surgical gear dressed in sterile dress to maintaindesignated pathogen free conditions prior to receiving the source animaland in some instanced be double-gloved to minimize contamination.

The operating area is prepared with materials required for harvestingskin from the source animal prior to decontamination (e.g., 24 hoursprior with chlorine dioxide gas treatment) and prior to the procedure.Dermatome (electronic skin harvesting device, e.g., Amalgatome byExsurco) power supply, and extension cord are sterilized and placed inthe operating area prior to the operation. Any materials not in the roomduring the chlorine dioxide gas treatment (and therefore non-sterile)will be sprayed with 70% ethanol or isopropanol prior to entering theroom.

The source animal is removed from the bag and container in an asepticfashion, for example, a human lifting the source animal from the bag andcontainer using sterilized gloves and/or sterilized device to aidlifting and minimize contamination. The source animal is scrubbed byoperating staff for at least 2 minutes with Chlorhexidine brushes overthe entire area of the animal where the operation will occur,periodically pouring Chlorhexidine over the area to ensure coverage.

The source animal is placed on its right lateral flank and dorsumtowards the operating table leaving the left lateral flank and dorsumexposed. The exposed surface is scrubbed to the extreme visible surgicalborders, and constrained by sterile drapes secured with towel clamps.The source animal is then scrubbed with opened Betadine brushes andsterile water rinse over the entire area of the animal where theoperation will occur for approximately 2 minutes.

This Chlorhexidine and Betadine mixture will sit on the source animalfor approximately 2 minutes, and staff (dressed in sterile dress tomaintain designated pathogen free conditions) will then rinse and drythe source animal with sterile water and sterile gauze. The sourceanimal's hair is removed so as to not impact the membrane or introduceanother element that would degrade the cells. Hair removal is done usingsterilized clippers and/or straight razor in the designated pathogenfree environment immediately post-mortem with a clean blade utilizing achlorhexidine lather. Staff will use the clippers and/or straight razor(lubricated in a sterile bath) to remove any remaining hair on theoperating site, taking care to not puncture the skin. This procedurewill be repeated (scrubbing to shaving) by turning the source animalonto the left lateral flank so as to expose the right side. The sourceanimal will be rinsed with sterile water and dried with sterile towelsand sprayed with 70% ethanol. The source animal will be inspectedvisually by the surgeon to ensure proper coverage of scrubbing. Afterthe sterile scrub and final shaving, the source animal is ready for skinharvest.

Skin Harvesting

Operators will be dressed in sterile dress in accordance with programand other standards to maintain designated pathogen free conditions. Alltissue from the source animal that will be used for xenotransplantationis harvested within 15 hours of the animal being sacrificed.

In one aspect, the source animal is laid on its side on an operatingtable. In this aspect, harvesting is done utilizing a dermatome circularblade, (for example and Amalgatome® SD). As the staff secures the animalin place, the surgeon determines the most appropriate width (e.g., 1, 2,3, or 4 inches) and uses the circular dermatome to remove strips ofsplit thickness skin grafts at a chosen thickness (e.g., 0.50 mm, 0.55mm, 0.62 mm).

By way of further example, the thickness of the skin grafts could rangefrom 0.01 mm to 4 mm, depending on the therapeutic needs at issue. Itwill also be understood that in some aspects a full thickness graft mayalso be utilized harvested with alternative harvesting and graftingprocedures known in the art. Graft sizes can range from 1 cm² to 1000cm² (or approximately 1 ft²). It will be understood that larger graftsizes are also possible depending on the application and harvestingtechnique utilized and size of the source animal. It will be understoodthat for all aspects, other depths could be utilized as well, dependingon the application and needs of the task at hand for therapeutic and/orother purposes.

In another aspect, skin harvesting involves surgically removing a skinflap from the animal first, then the skin flap is placed dermis-sidedown onto a harvest board (e.g., a solid board made of metal, plastic orother appropriate material) set upon on the operating table. In thisaspect, sterile padding material is added beneath the skin flap and ontop of the harvest board, to allow appropriate give for proper dermatomedevice function. The skin flap is then affixed to the harvest boardfirmly with steel clamps. Curved towel clamps are utilized on the sideof the skin flap opposite the clamps until the skin is firm and taut.The surgeon will choose the most appropriate thickness on the dermatomeand adjust per harvest conditions. The surgeon will use the dermatome onthe secured skin flap, with an assistant maintaining tension along thedermatome progress. A second assistant may also provide assistance withskin flap tension, and may use rat tooth forceps to pull the graftproduct emerging from the dermatome.

Grafts are trimmed to desired sizes. By way of example, sizes can be: 5cm×5 cm, with a total surface area of 25 cm² and uniform thickness ofapproximately 0.55 mm; 5 cm×15 cm, with a total surface area of 75 cm²and uniform thickness of approximately 0.55 mm; 8 cm×7.5 cm, with atotal surface area of 60 cm² and uniform thickness of approximately 0.55mm; 8 cm×15 cm with a total surface area of 120 cm² and uniformthickness of approximately 0.55 mm. It will be further understood thatcustomizable sizes (i.e., width, thickness and length) can be createddepending on patient needs, including larger sheets of skin can beharvested for use in xenotransplantation procedures.

The xenotransplantation product is further processed to be free ofaerobic and anaerobic bacteria, fungus, and mycoplasma. Under sterileconditions in a laminar flow hood in a drug product processing suiteusing applicable aseptic techniques, immediately after, within 1, 2, 3,4, 5, 6, 7, 8, 9, 10 seconds, within 10 seconds to 1 minute, within 1minute to 1 hour, within 1 hour to 15 hours, or within 15 hours to 24hours following harvest, the xenotransplantation product is placed intoan anti-microbial/anti-fungal bath (“antipathogen bath”). With regard toa skin product, this can occur after the skin product is trimmed to theproper dose size and shape (e.g., trimmed to squares, rectangles, orothers shapes of desired size(s))

The antipathogen bath includes ampicillin, ceftazidime, vancomyocin,amphotericin-B placed in a sterile container and the xenotransplantationproducts are diluted as outlined in the following Table 6 and added toRPMI-1640 medium as outlined in the following Table 7. In one aspect,about 10 mL of medium is removed from the bottle before adding the aboveitems.

TABLE 6 Approx. Vial Diluent Vol Approx. Drug Mg Vol Diluent availableconcentration Ceftazidime 1000 10.0 mL Sterile 10.8 mL 100 mg/mL waterAmpicillin 2000 10.0 mL Sterile 11 mL 180 mg/mL water Vancomycin 50010.0 mL Sterile 50 ug/mL water Amphotericin 50 5.0 mL Sterile 10 mg/mL Bwater

TABLE 7 Volume (mL) Final mg/500 mL added to 500 Drug ConcentrationsMedia mL RPMI 1640 Ceftazidime 500-2500 mg/L 250-1250 mg 2.5-10Ampicillin 500-2500 mg/L 250-1250 mg  1-6 Vancomycin 25-125 mg/L 10-75mg 0.25-2  Amphotericin 40-200 mg/L 20-100 mg  2-10 B Total volume added5.75-28 

It will be understood that while this example is directed toxenotransplantation skin products, other organs, including, but notlimited to, kidney, lung, heart, liver, pancreas, and other organs canbe bathed in the antipathogen bath in accordance with the presentinvention. The amounts of combination of drugs and other chemicals, andduration of exposure to such antipathogen bath, are performed tominimize the affect such exposure has on cell viability andmitochondrial activity to achieve both the desired antipathogen resultand minimal manipulation of the xenotransplantation products inaccordance with the present invention.

As an alternative, or in addition to, removing pathogens via theantipathogen bath, the products are made designated pathogen free by aprocess and system utilizing ultraviolet light. In this aspect, theoperator is dressed in sterile dress in accordance with institutionalstandards to maintain designated pathogen free conditions. The operatorwears eye protection safety glasses for ultraviolet light and lasers.

An ultraviolet laser lamp is set up in a laminar flow hood. Each of thefour corners of the lamp is placed on two container lids that arestacked on top of each other, i.e., four pairs of lids are used tosupport the lamp, or other supporting items, able to position the lampin a temporary or fixed position above the working surface of the hood.The distance from the lamp bulbs (2 bulb tubes total) to the floor ofthe hood is approximately 1.5 inches. The entire interior of the hood issprayed with alcohol, e.g., ethanol or isopropanol. The lamp is turnedon and the operator performs a calculation of time for desired exposurebased on lamp specifications, number of bulbs, and distance between thebulbs and the xenotransplantation product.

The operator pours two baths (one chlorhexidine and one alcohol) intotwo separate bowls and places the two bowls under the hood.

A package of new sterilized cryovials is placed under the hood. Cryovialcaps are unscrewed and placed into the chlorhexidine bath. Each cryovial(without cap) is then turned upside down and plunged open ended into thechlorhexidine bath, for one minute each and then set upright to air dry.Thereafter, the exterior of each cryovial is wiped with chlorhexidineand alcohol utilizing sterile gauze. The cryovial caps are removed fromthe chlorhexidine bath and placed on sterile gauze. The open ends ofeach vial were plunged into alcohol bath for 1 minute each and then setaside to air dry.

Xenotransplantation products recently obtained from theharvest/procurement phase in the surgical room are transferred into theproduct processing room, via a one-way entrance into the laminar flowhood. Anything entering the sterile field is wiped down with 70% ethanolprior to transfer to the operator. The operator will have access to allrequired materials in the laminar flow hood: xenotransplantation product(in sterile container), cryovials, 10 mL syringes and needles, phasefreezer holding rack, and pre-cut nylon mesh. Only one size of theproducts is processed at a time to ensure proper control to final vials.The operator is seated at the laminar flow hood in compliance withsterile, aseptic techniques.

When using UV light sterilization, the product is placed under the UVlamp for a desired period of time, e.g., 2 minutes or more, then turnedover to the other side, and put under the UV lamp for the same period oftime, e.g., 2 minutes or more on opposite side. The time period forexposing a given sample to the UV is varied based on the specificbiological agents or the types of biological agents to be sterilized,e.g., as shown in the following Table 8:

TABLE 8 Type of UV-C Dosage Sterilization Biological (uW sec/cm²) timeBiological Agent Agent for 90% sterilization (sec)* Penicillium spp.Fungus 224,000 1800 Aspergillus flavus Fungus 34,900 300 Aspergillusniger Fungus 31,500 250 Yeast Fungus 4000 30 Influenza A Virus 1900 15HIV-1 Virus 28,000 220 Vaccinia Virus 1500 10 Escherichia coli Bacteria2000 20 Staphylococcus Bacteria 6600 50 aureus Bacillus subtilisBacteria 6800 50 Mycoplasma spp. Bacteria 8400 70 Pseudomonas Bacteria2200 20 aeruginosa *Using a UV-C intensity of 125 uW/cm²

With regard to other whole organs, product yield will typically dependon how many of each such whole organ a given source animal may have(e.g., one liver, two lungs, two kidneys, one heart, one pancreas and soforth).

It will also be understood that while this example is directed toxenotransplantation skin products, other organs, including, but notlimited to, kidney, heart, lung, liver, pancreas, and other organs canbe exposed to ultraviolet light and made designated pathogen free inaccordance with the present invention. The UV exposure dosages,intensity, and duration of exposure to such ultraviolet light, areperformed to minimize the affect such exposure has on cell viability andmitochondrial activity to achieve both the desired antipathogen resultand minimal manipulation of the xenotransplantation products inaccordance with the present invention.

Manufacturing Process Generally

Through the continuous manufacturing event, source animals are processedinto aseptic xenotransplantation products. Several items are involved inthe manufacture of the product relating to the source animals,including, but not limited to:

-   -   a. care and husbandry of the source animals (including, as        described herein, providing certain vaccinations, carefully        maintaining and analyzing pedigree records, performing proper        animal husbandry, and maintaining the animals in isolation        barrier conditions);    -   b. product manufacturing (including, as described herein,        processing the source animals into the subject product from        euthanizing to harvest);    -   c. analytical testing of the source animals (including, as        described herein, screening for adventitious agents including        parasitology, bacteriology, and virology assays);    -   d. analytical testing of the source animals (including, as        described herein, confirming the source animal is an        alpha-1,3-galactotransferase knockout or has other        characteristics that are desired for a given application); and    -   e. analytical testing of the source animals (including, as        described herein, viral assay for Endogenous Viruses (PERV)).

Several items are also involved in the manufacture and release testingof the resulting products, including, but not limited to:

-   -   a. product manufacturing (including, as described herein,        processing the drug product, storing the drug product, and        releasing the drug product);    -   b. analytical testing of the drug product (including, as        described herein, viability testing (via, e.g., MTT assay)),    -   c. sterility testing (including, as described herein, aerobic        bacteria culture, anaerobic bacteria culture, fungal culture,        mycoplasma assay, endotoxin test, USP <71>)),    -   d. adventitious agent testing (including, as described herein,        PCR Assay for e.g., Endogenous Viruses (PERV)); and    -   e. analytical testing of the drug product (including, as        described herein, histology).

For skin, the quantity of product yield from each animal can varydepending on the size of each animal. By way of example, some animalscould yield between 3,000 and 6,000 cm² in product. In one aspect, asingle batch of skin product is harvested from a single source animal ina continuous process. A batch description of the xenotransplantationproduct is provided in Table 9 and batch formula for thexenotransplantation product is provided in Table 10.

TABLE 9 Batch Size Product (strength) Lot Size Xenotransplantationproduct Drug Product, 200 Units (180-220) Dosage Strength 1 (7.5 grams,25 cm²) (1.5 kgs per lot) (1.35 kg to 1.65 kg) Xenotransplantationproduct Drug Product, 67 units (60-75) Dosage Strength 2 (22.5 grams, 75cm²) (1.5 kgs per lot) (1.35 kg to 1.65 kg)

TABLE 10 Batch Formula Nominal Amount Nominal Amount Component per Vialper Lot Xenotransplantation 25 cm² 200 Units product Drug SubstanceDosage Strength 1 CryoStor 7 ml 1.4 L Nylon Mesh 60 cm² 1200 cm² TotalBatch Size 7.5 grams 1.5 kgs Xenotransplantation 75 cm² 67 Units productDrug Substance Dosage Strength 1 CryoStor 5 ml 350 ml Nylon Mesh 180 cm²3600 cm² Total Batch Size 22.5 grams 1.5 kgs

Prior lot testing is performed under good laboratory practice (“GLP”)conditions to ensure process sterility is maintained consistently.Assurance of sterility of the final product is determined prior tomaterial release and clinical use. Prior to validation for humanclinical use, all xenotransplantation products will meet certainacceptance criteria, including as described herein. The final drugproduct control strategy and analytical testing is conducted at theconclusion of the manufacturing process prior to release for clinicaluse. Results of the required analytical tests will be documented via adrug product certificate of analysis (COA) that is maintained with amaster batch record pertaining to each lot of xenotransplantationproducts.

Source animal sample archives are generated and maintained throughprocurement of tissue samples of lung, liver, spleen, spinal cord,brain, kidney, and skin. These tissues are collected for source animaltissues for testing, archive, and stored for potential future testing.Archived samples of source animal tissue and bodily fluids should bestored at minus (−) 70 degrees Celsius or lower, as appropriate forpreserving the sample. In other aspects, fixed samples can be maintainedat room temperature. Appropriate tissue samples should be collected forformalin fixation and paraffin-embedding and for cryopreservation fromsource animals at the time the live cells, tissues, or organs areprocured. Cryopreservation should be at least ten 0.5 cc aliquots ofcitrated- or EDTA-anticoagulated plasma; five aliquots of viableleukocytes (1×107/aliquot, for subsequent isolation of nucleic acids andproteins or for use as a source of viable cells for co-culture or othertissue culture assays.

Product Processing Following Harvesting

The previously harvested and minimally manipulated xenotransplantationskin product (here the skin integrity being minimally manipulated dermaland epidermal tissue layers with standard cellular morphology andorganization) enters the separate, adjacent room with positive pressureabove that of the surgical suite, designated as the Class 10,000 (IS0-7)product processing room.

The operating room will be setup per operating preparation proceduresand the operating personnel will be dressed in Tyvex suits for fume hoodwork. If requested, an assistant will also be dressed in a Tyvex suit.Gowning and Dressing is done with aseptic techniques. Gloves and sleeveswill be sprayed with alcohol if needed. The ABSL-2 laminar flow hood,having been prior sterilized via gaseous chlorine dioxide sterilizationprocess, will be sprayed with alcohol, e.g, 70% ethanol, and the laminarflow exhaust will be initiated. Utilizing aseptic techniques, previouslysterilized via autoclave, surgical instrument, cryovials, cryotray,flasks, syringes, needles, additional containers, and all processingequipment will be placed within the laminar flow hood. Exteriorpackaging is sprayed with alcohol prior to being transferred to theoperator.

As described herein, prior to operation, nylon mesh graft backing shouldbe cut into squares of appropriate size for the dosage levels, sealed inan autoclavable pouch, and sterilized via steam. Exterior of pouch willthen be sterilized with 70% ethanol and placed in the fume hood.Exterior package of 10 mL Cryovials will be decontaminated with 70%ethanol and placed into the fume hood. Sterile, autoclaved surgicalinstrument package should be sprayed with 70% ethanol and transferred tothe operator.

Sterile syringes and needles should be sprayed with 70% ethanol andtransferred to the operator. Graft tissue recently harvest form theporcine donor will be transferred to the hood. Anything entering thesterile field is wiped down with 70% ethanol prior to transfer to theoperator. Operator will have access to all required materials in thefume hood: Grafts (in sterile container), Cryovials, 10 mL syringes andneedles, Phase Freezer holding rack, and cut Nylon mesh. Operator shouldbe seated at the fume hood with in compliance with sterile, aseptictechnique.

Referring to FIG. 2, each cryovial will be sterilized and labeled inadvance to reduce processing time and unnecessary material exposure toDMSO prior to cryopreservation. Pans containing each xenotransplantationproduct and the RPMI 1640 Tissue Culture Media at room temperature withantibiotics (e.g., antipathogen bath) is placed under the laminar flowhood. The products had been bathing in the anti-pathogen bath for notless than 30 minutes to sterilize the xenotransplantation product.

In one aspect, when using UV light sterilization, the cryovials aresterilized using the UV lamp as described above. After the product isinserted into each vial, each new cap is placed on each new vial andscrewed on securely. Each vial is placed under the lamp and periodicallyrolled for desired even exposure to light on the exterior of the vial.The vials are placed inside a glass jar that has an interior that hasbeen previously sterilized and the exterior is sterilized by theoperator with alcohol and chlorhexidine, including threads and caps.Vials are wiped down with alcohol and are placed into glass jars. Theexteriors of the glass jars are drenched with alcohol outside of thehood. Under the hood, the operator bathes the glass jar lids and plungesthe open ends of the jars into alcohol and wipes the exterior of thejars with alcohol (and optionally chlorhexidine) including threads ofthe jar. The vials are wiped with alcohol utilizing gauze and placedinside each glass jar with an instrument. The lids of the glass jars arethen secured and the jars are handed to the assistant. Frequently and ona periodic basis throughout these processes, the assistant sprays theoperator's gloves and arms with alcohol.

In this example, the xenotransplantation skin product, which was cut toform in the surgical suite with sterile scissors and was trimmed with10-blade scalpel, will be re-measured with a sterile, stainless steelruler to verify technical specifications and dimensions have been met.The xenotransplantation skin product is visually inspected to ensure norips, tears, observable defects, or excessive or insufficient thicknessare present.

Under the laminar flow hood the operator will use forceps to take asingle xenotransplantation skin product from the antipathogen bath andplace it upon a piece of nylon mesh that has been previously cut to fitthe cryovial, centered on the nylon mesh, with the dermis side incontact with the mesh (e.g., dermis side down), taking 1 minute for eachproduct (understanding the time could be less or more, and up to 5minutes for each product). It will be understood that the sterile nylonmesh packaging component is utilized, among other things, to support thexenotransplantation product and prevent self-adhesion of thexenotransplantation product when rolled.

It will be further understood that the sterile nylon mesh packagingcomponent can be of any dimension that would allow thexenotransplantation product to be placed onto the sterile nylon meshpackaging component and fit within the two dimensional surface area(i.e., the length and width not including the thickness) of the sterilenylon mesh packaging component (e.g., the two dimensional area dimensionof the xenotransplantation product would be less than the twodimensional area dimension of the sterile nylon mesh packagingcomponent).

It will be further understood that the dimensions of the sterile nylonmesh packaging component would be sized in accordance with thexenotransplantation product size and dosage. For example, the sterilenylon mesh packaging component is 8 cm×7.5 cm (60 cm²) to fit a 5 cm×5cm xenotransplantation skin product (25 cm²) (7.5 grams) utilizing 7 mlof cryoprotective media when placed in the cryovial. It will be evenfurther understood that the dimensions of the sterile nylon meshpackaging component is 8 cm×22.5 cm (180 cm²) to fit a 5 cm×15 cmxenotransplantation skin product (75 cm²) (22.5 grams) utilizing 5 ml ofcryoprotective media when placed in the cryovial.

Unintentional adhesion of epidermal or dermal regions of thexenotransplantation skin product during packaging may disrupt theintegrity of the xenotransplantation skin product and potentially reduceits therapeutic viability. Inclusion of the sterile nylon-mesh packagingcomponent is intended to provide internal physical support to andprevent self-adhesion. The sterile nylon-mesh packaging component is notbiologically or chemically active and does not directly impact themetabolic activity or efficacy of the xenotransplantation skin productitself.

During the course of numerous experiments, including the monkey studiesdescribed in Example 1 herein, use of this sterile nylon-mesh packagingcomponent has never been observed to cause an adverse, undesiredreaction with the xenotransplantation product, or degrade andcontaminate the final xenotransplantation product causing adversereactions or outcomes to the recipient. The sterile, nylon-meshpackaging component is not used in the grafting procedure. Followingcryopreservation and thawing, and prior to use of thexenotransplantation product, it is discarded. Thus, selection of thespecific material and associated specifications were carefully chosenfor the given application. Medifab 100-Micron Nylon Mesh (Part#03-100/32-Medifab) is manufactured per cGMP standards, and was selectedbecause of its physical characteristics and certified acceptability forhuman, clinical use.

Under the laminar flow hood, the operator will then tightly roll thiscombination of xenotransplantation product and nylon mesh packagingcomponent and place the combination within a cryovial (e.g., 10 ml vial)taking 1 minute for each product (understanding the time could be lessor more, and up to 5 minutes for each product). In this aspect, the meshmaterial is rolled to ensure that the vertical height of the cylinder is8 cm and uniformly fits within the 10 ml cryovial (e.g., 10 cm lengthand 17 mm diameter) and once completed, can be secured with a threadedseal cap. The mesh material is oriented such that the protective meshmaterial is on the exterior of the xenotransplantation product, and thatonce the rolled is complete there is no exposed or visiblexenotransplantation material and it is fully encased in the protectiveinsert. The intrinsic tensile and material properties of the sterilenylon-mesh packaging component are homogenous, and the inelasticity orstiffness of the material causes it to expand to fill the volume of thecryovial. Thus, regardless of the initial “roll-density”, the materialwill uniformly loosen and is therefore standardized.

Under the laminar flow hood the operator will then use a sterile syringeto draw up enough sterile cryoprotective media (e.g., 5-7 ml of themedia with 5% dimethyl sulfoxide (DMSO) (Cryostor CS5, BioLifeSolutions)) to fill the cryovial until the skin product roll is fullyimmersed, ensuring that the combination of xenotransplantation skinmaterial, mesh backing, and cryoprotectant media is flush with the 10 mlfill line, taking 1 minute for each product (understanding the timecould be less or more, and up to 5 minutes for each product).

Under the laminar flow hood, the operator will seal the cryovial withthe threaded cap. The identity of the contents and label information areconfirmed by the operator. Labels are prepopulated and applied to theexterior of the cryovials containing the product in advance of theproduct processing.

It will be understood that the preparation of the xenotransplantationproducts and packaging components described herein could be in the formof therapeutic dosages. For example, the xenotransplantation drugproduct consists of:

-   -   a. Xenotransplantation split-thickness skin Drug Substance    -   b. Primary Container Closure System which includes        -   i. Primary Packaging Component: a sterile, clear,            polypropylene 10 ml cryovial with threaded seal-cap        -   ii. Sterile nylon-mesh packaging component        -   iii. Cryoprotective media packaging component            The indicated dosage of Xenotransplantation product is 300            mg of vital, metabolically active, porcine            xenotransplantation drug substance per cm², with a constant            thickness of 0.55 mm. Example formulations include:    -   c. Dosage Strength 1: a 25 cm² split thickness skin graft, with        uniform thickness of 0.55 mm, which weighs approximately 7.5        grams.    -   d. Dosage Strength 2: a 75 cm² split thickness skin graft, with        uniform thickness of 0.55 mm, which weights approximately 22.5        grams.

An example xenotransplantation drug product primary packaging componentis a sterile, clear, polypropylene 10 ml cryovial with threadedseal-cap. For example, the Simport Cryovial, T310 (10-ml) ismanufactured by Simport Scientific. This product is composed of medicalgrade resin that is BPA free, Heavy Metal Free, and LATEX Free and meetsUSP Class VI limits.

A nylon-mesh packaging component is utilized during thexenotransplantation drug product manufacturing process. The preparedxenotransplantation drug product is placed on sterile nylon-meshpackaging component (e.g., Medifab 100-Micron Nylon Mesh) that has beenpreviously trimmed to the following dimensions:

-   -   a. Dosage Strength 1: 7.5 cm in width by 8 cm in height; total        area of 60 cm²    -   b. Dosage Strength 2: 22.5 cm in width by 8 cm in height; total        area of 180 cm²

A cryoprotective media packaging component is also utilized during thedrug manufacturing process. The xenotransplantation drug product isimmersed in the following volumes of cryoprotective media packagingcomponent prior to cryopreservation:

-   -   a. Dosage Strength 1: 7 ml of Cryostor CS5 (containing 5% DMSO).    -   b. Dosage Strength 2: 5 ml of Cryostor CS5 (containing 5% DMSO).

With regard to the assurance of saturation of cryoprotective media, theindicated amount of CryoStor CS5 media (per Dosage Strength) is appliedvia 10 ml syringe with the cryovial (such as a type of cryovial shown inFIG. 30) in the vertical position, under a laminar flow hood (ISO-5, FEDSTD 209E Class 100 conditions) Cryomedia fills the voided space(s), andgravity ensures that the fill-process begins from the base of thevertically oriented cryovial towards the fill line at the apex. Volumeis added until it reaches the manufacturers demarcated 10 ml fill line.Filling the vial in this manner also facilitates the removal of airbubbles. Once complete, the threaded cap is sealed. Visual and physicalverification of saturation and fill is accomplished, ensuring thatcontents the xenotransplantation product are unable to shift internally.

Cryopreservation

Product materials will be placed in the appropriate freezer rackcontaining cryovials with product as described above, and placed in acertified, Q-A control rate-phase freezer. Using a certified, Q-Acontrol rate-phase freezer, the entire product is cryopreserved via onestandardized control-rate freezing process:

-   -   a. Starting at 4° C., internal chamber and sample temperature        probe will lower at a rate of 1° Celsius per minute until a        temperature of −40° C. is achieved.    -   b. Once temperature of −40° C. has been reached in a controlled        rate, control-rate freezer sample temperature probe should lower        rapidly from −40° C. to −80° C.    -   c. Material is then transferred to a GLP certified, −80° C.        freezer until use.        Taking 40 minutes per batch time from room temperature to        −80° C. (understanding the time could be less or more, and up to        2 hours). In some aspects, penetrative cryoprotectants such as        DMSO, may be used to protect morphology and tissue structure,        and retain metabolic activity levels comparable to that of fresh        skin. In some aspects, cryopreservation may alternatively or        additionally include one or more of glycerol, gentamicin,        Nystatin, L-glutamine, and other processing solutions. In some        aspects, β-lactam antibiotics are not used.

Inclusion of the cryoprotective-media packaging component is intended tosupport cell survival during the freeze-thaw cycle required for thexenotransplantation product. Failure to include the cryoprotective mediapackaging component of xenotransplantation product during packaging maydisrupt the integrity of the xenotransplantation product or impede thecryopreservation process, and may potentially reduce thexenotransplantation product viability below acceptance criteria.Cryopreservation of the xenotransplantation product without inclusion acryoprotective media results in destruction of biologically active cellscontained in the xenotransplantation product. Rapid formation of icecrystals and disruption of cellular membranes and mitochondrialorganelle barriers occurs during the freezing process, and thedimethyl-sulfoxide ingredient acts to displace intracellular fluid.Thus, the cryoprotective media reduces the formation of such icecrystals and rapid, disruptive increase in total cellular volume thatwould negatively impact the cellular viability and, thus, the efficacyof the Drug Product.

During the course of a number of experiments, including the monkeystudies in Example 1 herein, use of this cryoprotective-media packagingcomponent has never been observed to cause an adverse, undesiredreaction with the xenotransplantation product, or degrade andcontaminate the final xenotransplantation product causing adversereactions or outcomes to the recipient. Thus, selection of the specificmaterial and associated specifications were chosen to meet appropriatestandards necessary of a xenotransplantation product intended for human,clinical use. This including identifying a cryoprotective media withminimal, subclinical levels of DMSO, one that would satisfactorilyperform without the need for inclusion of an additionalxenotransplantation material (porcine serum) in the formulation. Thecryoprotective media-packaging component is not used in the graftingprocedure. Upon thawing, and prior to use of the xenotransplantation fortherapeutic uses including as a drug product, it is discarded. CryoStorCS5 is manufactured per cGMP standards and was selected because of itscertified acceptability for human, clinical use.

Shipping to Clinical Site

Shipping the product to the clinical site should be done to maintain thexenotransplantation skin product material at −80° C. storage condition.One example shipping container is the EXP-6 Standard Dry Vapor Shipperhaving an extensive, having the following specifications:

-   -   Dynamic Holding Time 10 Days    -   Holding Temperature −150° C. or Colder    -   Core Technology Dry Vapor Liquid Nitrogen    -   Specimen Chamber 2.8″ (71 mm) Diameter    -   11.5″ (292 mm) Depth    -   Weight Dry 9.7 lbs/4.4 kg    -   Charged 18.3 lbs/8.3 kg    -   Domestic Dimensional 21.07 lbs/9.56 kg    -   International Dimensional 24.87 lbs/11.28 kg    -   Outer Box 12″×12″×22″    -   (305×305×559 mm)        Aspects of the shipping process are also shown in FIG. 29        including, but not limited to, (1) cryopreservation storage; (2)        xenotransplantation product in cryovial and media as described        herein while in cryopreservation storage; (3) cryovial placed in        dry vapor shipping container (or secondary closure system); (4)        container and vial shipped via courier; (5) xenotransplantation        product controlled and monitored at delivery location (can last        at least 10 days at minus (−) 150 degrees Celsius or        colder); (6) xenotransplantation product in cryovial and media        as described herein removed from container/secondary closure        system; (7) xenotransplantation product in cryovial and media as        described herein placed in freezer at location being stored at        −80° C.

Clinical Site Preparation

In one aspect, the drug product arrives at the clinical site as acryopreserved xenotransplantation product. Prior to use, thexenotransplantation product must be thawed in a 37° C. water bath,removed from the vial and washed in a series of 3 sterile 0.9% salinebaths at room temperature.

For the thawing process, sterile equipment and aseptic techniques areused:

-   -   a. Prepare 200 mL of normal saline into each of three 500 mL        sterile, surgical bowls.    -   b. Place the unopened cryovial with the skin product in water        bath having a temperature of about 25° C. In some embodiments,        the temperature is about 37° C.    -   c. In the bath, swirl gently for approximately 5 minutes or        until tissue is mobile within the cryovial, taking care to        minimize unnecessary exposure time the xenotransplantation skin        product tissue is suspended in the thawed DMSO as much as        possible.    -   d. Open the cryovial and use sterile forceps to quickly remove        tissue and mesh to transfer into a bowl of normal saline.    -   e. Using sterile forceps, ensure tissue is fully submerged in        saline for 15 seconds, agitating by swirling gently to maximize        coverage. The underlying, supportive mesh material should be        separated from the skin xenotransplantation skin product        material. Use a second pair of sterile forceps to separate if        necessary. Mesh can be left in the bowl, or discarded.    -   f. Using sterile forceps, transfer the skin into a second bowl        wash. Submerge fully and gently swirl for 15 seconds; this is a        serial dilution or “rinse”.    -   g. Repeat the previous step, using sterile forceps to transfer        the skin into a third wash of normal saline. Submerge fully and        gently swirl for about 15 seconds.    -   h. The entire duration of the rinse process should be completed        within 60 seconds to minimize unnecessary exposure time the        product is suspended in thawed DMSO in order to maximize product        efficacy.    -   i. Tissue is now thawed, rinsed, and ready for application.        Leave in normal saline until use, not to exceed 2 hours at about        25° C.

After the complete, thaw and rinse process is complete, thexenotransplantation product is ready for placement on the wound site.Serial washes in saline, once thawed provide ample dilutive solvent toremove the residual cryoprotectant (5% DMSO solution, CryoStor CS5) andreplace the intracellular fluid levels to normal homeostatic conditions.Such dilution and use of a cryoprotective media containing asub-clinical level of DMSO ensures that any minimal, residual DMSOremaining on the xenotransplantation skin product material post-thawwould be non-appreciable and would be highly unlikely to be clinicallysignificant. This process also ensures retention of the maximum amountof metabolically active cells, and thereby maximizing the efficacy ofthe xenotransplantation product.

Example of Thawing. Following is one example of a thawing procedure fora xenotransplantation product. Thawing can occur in a BioSafety Cabinetwith operator in sterile gloves as follows: (i) prepare 200 mL of Normalsaline into each of three 500 mL surgical bowls; (ii) prepare the waterbath by wiping it clean with chlorhexidine then spraying it down with70% ethanol; (iii) after the ethanol has dried add sterile watersolution into the water bath and heat to 37° C.+/−2° C.; (iv) thexenotransplantation drug product is in a double bag, leave it unopenedand place it into the 37° C. water bath; (v) swirl gently forapproximately 5 minutes or until the tissue is mobile within thecryovial; (vi) minimize the time the tissue spends in thawed DMSO asmuch as possible; (vii) spray the outside bags with ethanol and removethe vial from the outer bags and spray the xenotransplantation drugproduct cryovials with 70% ethanol before placing into BiosafetyCabinet; (viii) unscrew the cryovial and use forceps to quickly removetissue and mesh to transfer into a bowl of normal saline; (ix) useforceps to ensure tissue is fully submerged in saline for 60 seconds,agitating by swirling gently to maximize coverage; (x) the mesh shouldbe separated from the skin, using a second pair of forceps to separateif necessary; (xi) the mesh can be left in the bowl, or discarded; (xii)using forceps transfer the skin into the second bowl wash; (xiii)submerge fully and gently swirl for 60 seconds; (xiv) using forcepstransfer the skin into the third bowl wash and submerge fully and gentlyswirl for 60 seconds. Tissue is now thawed and ready for application.Keep it moist with sterile saline in a sterile pan.

The process of rolling the inert, nylon mesh backing and thexenotransplantation skin product results in uniform “roll-density” ofthe xenotransplantation product. All mesh materials are cut to uniformdimensions, according to the prescribed dimensions for the givenapplication, and are obtained from the same material lot, thus affordinguniform material properties for all units of the skin productmanufactured within a specific lot.

The intrinsic tensile and material properties of the nylon mesh insertare homogenous, and the inelasticity or stiffness of the material causesit to expand to fill the volume of the primary container closure system(cryovial). Thus, regardless of the initial “roll-density”, the materialwill uniformly loosen and is therefore standardized.

The indicated amount of CryoStor CS5 media (per Dosage Strength) isapplied via 10 ml-syringe with the cryovial in the vertical position,under Class 100, IS05 conditions within an ABSL-2 laminar flow hood.

Cryomedia fills the voided space(s), and gravity ensures that thefill-process begins from the base of the vertically oriented cryovialtowards the fill line at the apex. Volume is added until it reaches themanufacturers demarcated 10 ml fill line. Filling the vial in thismanner also facilitates the removal of air bubbles.

Once complete, the threaded cap is sealed. Visual and physical assuranceof saturation and fill is accomplished by the shaking the skin productensuring that contents are unable to shift internally. Aspects of thecryovial are also shown in FIG. 30, with aspects that can include, amongother things, 10 ml volume, size of 17 mm×84 mm, vertical ribsfacilitating cap removal, silicone washer, cap and tube made of the samepolypropylene material with the same coefficient of expansion ensuringseal at all temperatures, 1 and ¼ turn thread design, thick wall, largewhite marking area, and round bottom allowing for ease of emptyingcontents.

Aspects of the secondary closure system is shown in FIG. 31, withaspects that can include, among other things, Tyvek-1073B medical gradeconstruction, 5 inches wide×12″ high, storage ability of 15 cames or 2cryovial boxes, holding temperature of −150 degrees Celsius or colder,utilization of dry vapor liquid nitrogen, IATA rated 10 days of dynamicholding time under normal shipping conditions, specimen chamber diameterof 2.8 inches (71 mm), specimen chamber depth of 11.5 inches (292 mm),dry weight of 9.7 lbs/4.4 kg, charged weight of 18.3 lbs./8.3 kg,domestic dimensional weight of 21.07 lbs./9.56 kg, internationaldimensional weight of 24.87 lbs./11.28 kg, outer box dimensions of12″×12″×22.″

No additional or external impurities in the product are anticipated tobe present since processing involves only the minimal mechanicalmanipulation of the product, and no other chemical or biological agentsare introduced during this closed process. Acceptance criteria testingrequired for use of the source animals for the product manufacturingprocess is conducted as described herein and documented via the DrugProduct COA. The final product is evaluated for viral adventitiousagents as described herein.

In terms of shelf life, continuous storage of the xenotransplantationproduct as described support a shelf life long-term stability(cell-viability) of up to at least 7 years (in one embodiment is a shelflife of 6 months) when stored continuously at −80° C. The shelf-lifeduration of continued cryopreservation of the xenotransplantationproduct with of at least 7 years. Table 11 shows stability time pointsthat the xenotransplantation product will be tested.

TABLE 11 Stability Study Time Points Time points (Months) Assay 0 12 2436 60 Histology A B B B B Sterility A B B B B Endotoxin A B B B BViability A B B B B A = initial product release testing B = stabilitytesting for Xenotransplantation product

In accordance with one aspect, following in Table 12 are items that canbe utilized in a certificate of analysis and release.

TABLE 12 Test Results Test Method Acceptance Criteria Results AppearanceVisual Inspection Clear, colorless to slightly Conforms yellow liquidwith no visible particulates pH TM5110 7.5 to 7.7 7.6 USP <791>Metabolic TMSlOO Cell viability is 75% to 87 Activity Assay 200% ofcells preserved in the internal standard at Day 1 recovery followingpreservation. Endotoxin Kinetic Chromogenic s 0.5 EU/ml Conforms USP<85> Sterility Membrane Filtration Sterile Conforms USP <71>Identification TMSlll FT-IR Conforms to CryoStor CSS Conforms ReferenceStandard Osmolality TM 5112 1360-1390 mOsm/kgH20 1388 USP <785> SpecificGravity TM5114 1.055-1.063 1.059 DMSO Content Gas Chromatography4.0%-7.0% 5.0 (FID)

Example 3 Dermis Epidermus Combo Product

The following example provides a description of a skin product derivedfrom a designated pathogen free α-1,3-galactosyltransferase [Gal-T]knockout swine for use in human transplantation produced in accordancewith the present invention. The product, process and techniquesdisclosed herein are but examples, and do not limit the scope of theinvention.

Some skin transplantation products for the treatment of burns and otherailments utilize cultured epidermal autografts (see, e.g., productsproduced by Vericel Corporation under the Epicel® brand name). Suchepidermal autografts can be utilized for patients with burns (includingsevere burns) and result in reduced or no rejection in the transplantedepidermal material since the material is derived from the patient's ownskin.

However, such products are limited to the epidermis only, and do notinclude the dermis portion of the skin. Referring to FIG. 3, it will beunderstood that the dermis (which typically accounts for 95% of thethickness of the skin) performs significantly different functions thanthe epidermis (which is the outer portion of the skin that typicallyaccounts for 5% of the thickness of the skin).

Since epidermal autografts alone lack the ability to perform thecritical functions of the dermis, such products are used in combinationwith a viable dermis. In some injuries, the wound bed includes remainingportions of the patient's own dermis, which is the ideal dermis toutilize in a procedure grafting cultured epidermal autografts onto apatient. However, in some cases the burn is more severe, and thepatient's own dermis no longer exists or is no longer viable. In thoseinstances, a different dermis is required since an epidermal autograftalone will not suffice.

In one aspect, a full thickness skin graft wound dressing consisting ofdermal tissue derived from designated pathogen freeα-1,3-galactosyltransferase [Gal-T] knockout swine in accordance withthe present invention is used in conjunction or combination withcultured epidermal autografts. One treatment process utilizing thiscombination is as follows.

A patient with severe burn wounds is taken to an operating room within48-72 hours of injury. A biopsy is taken as soon as possible after thepatient undergoes care, and the epidermis skin cells are isolated andgrown separately according to the known procedures for creating culturedepidermal autografts (see, e.g., products produced by VericelCorporation under the Epicel® brand name).

Depending on how much of the patient's body is damaged, epidermalautografts are taken from healthy areas to treat burned areas and/or tolater create an epidermal autograft mesh used in the grafting process.

Areas of severe burns are treated with the skin products describedherein, e.g., skin products derived from a designated pathogen freeα-1,3-galactosyltransferase [Gal-T] knockout swine produced inaccordance with the present invention. Such treatments comprisetemporary wound coverage until sufficient autografts are utilized totreat the patient long-term.

Prior to application of the epidermal autografts, significantdebridement of wound bed is required to ensure an adequate substrate. Toconfirm a wound bed is ready for an epidermal autograft, apply the skinproducts described herein, e.g., skin products derived from a designatedpathogen free α-1,3-galactosyltransferase [Gal-T] knockout swineproduced in accordance with the present invention to confirm adherence.Once adherence is confirmed, the temporary wound coverage product isremoved, and in some aspects, the wound bed is covered with a meshedautograft, and one or more cultured epidermal autograft products areplaced on top to close the gaps in the autograft mesh.

The debridement may include mechanical debridement, chemicaldebridement, enzymatic debridement, or a combination thereof. Mechanicaldebridement may include surgical excision, e.g., tangential excision toremove thin layers of dermis until healthy tissue is visualized, orfascial excision to remove the full thickness of dermis down to theunderlying fascia. Tangential excision allows less viable tissue to beremoved with the necrotic tissue, but typically results in higher bloodloss, is a larger physiologic stressor than fascial excision, and ismore likely to result in “incomplete” debridement, with some devitalizedtissue remaining in place. In fascial excision, blood loss and operativetime are minimized, but often a large amount of healthy tissue isremoved with the burned tissue. Debriding agents may include agentscapable of cleaning a burn wound by removing foreign material and deadtissue. Many such agents are known. In enzymatic debridement,collagenases or other proteolytic enzymes are employed that break downproteins of the extracellular matrix, allowing devitalized tissue to bewiped away without the need for surgery while preferably leaving healthytissue substantially intact. Enzymatic debridement involves theapplication of proteolytic and optionally other exogenous enzymes to awound surface to break down necrotic tissue. Enzymatic debridement maybe a relatively slow process, carried out over a period of a number ofweeks in combination with other topical preparations, soakings andrepeated dressings. Alternately, rapid enzymatic debridement can beaccomplished using multi-enzyme products, for example, those extractedfrom the stem of the pineapple plant, as disclosed for example in WO98/053850 and WO 2006/0006167, and as provided in the product marketedunder the trade name Debrase®. A procedure for enzymatic debridementgenerally utilizes an enzyme such as bromelain derivatives, debridase,collagenase, papain derivatives, streptokinase, sutilains, fibrinolysin,deoxyribonuclease, hill derivatives, trypsin or combinations thereof.Autolytic debridement relies on enhancing the natural process ofselective liquefaction, separation and digestion of necrotic tissue andeschar from healthy tissue that occurs in wounds due to macrophage andendogenous proteolytic activity. This is achieved by the use ofocclusive, semi-occlusive or moist interactive dressings. Enzymaticdebridement agents include a bromelain enriched enzyme product, othercollagenases, or other enzyme products capable of clearing devitalizedtissue or wound debris. NexoBrid™ (MediWound Ltd.) is one such bromelainenriched product that specifically targets heat-denatured collagen fordegradation, resulting in partial-thickness and full-thickness woundsrequiring a wound coverage or dressing product. Such products andmethods are described in U.S. Pat. Nos. 8,540,983; 8,119,124; 7,128,719;7,794,709; 8,624,077; and US2009/0010910A1, each of which isincorporated by reference herein.

In some aspects, the wound bed may include or be a chronic wound or anacute wound. Chronic wounds include but are not limited to venous legulcers, pressure ulcers, and diabetic foot ulcers. Acute wounds includebut are not limited to burns, traumatic injuries, amputation wounds,skin graft donor sites, bite wounds, frostbite wounds, dermabrasions,and surgical wounds.

In the cases where there is no dermis, skin products derived from adesignated pathogen free α-1,3-galactosyltransferase [Gal-T] knockoutswine produced in accordance with the present invention are utilized.The epidermis is removed from such products (e.g., before dermisharvesting on the pig with a VERSAJET™ Hydrosurgery system), so thatjust the dermis remains. Then, the subject swine dermis is placed on thepatient's subcutaneous tissue, serving as a substrate for the culturedepidermal autograft process described above.

Example 4 DPF Xenogeneic Liver Filter

Use of transgenic pig livers to serve as extracorporeal filters inhumans is disclosed in Levy, et al., “Liver allotransplantation afterextracorporeal hepatic support with transgenic (hCD55/hCD59) porcinelivers: Clinical results and lack of pig-to-human transmission of theporcine endogenous retrovirus,” Transplantation, 69(2):272-280 (2000)(“Levy”), the entire contents of which are incorporated herein byreference.

In that study, whole organ extracorporeal perfusion of a geneticallymodified transgenic porcine liver was proposed to sustain patientsawaiting human liver transplantation for fulminant hepatic failure. Thepig livers used were reported to be transgenic for human CD55(decay-accelerating factor) and human CD59, however, the livers failedto suppress marked increase of [alpha]-gal antibodies.

In accordance with the present invention, in one aspect, a liver derivedfrom a DPF Closed Colony, α-1,3-galactosyltransferase [Gal-T] knockoutpig in accordance with the present invention is utilized forextracorporeal perfusion as a temporary filter for a human patient untila patient receives a human transplant. It will be understood that pigswith additional genetic modifications may also be utilized, includingpigs genetically reprogrammed for any number of traits listed in Table 1and elsewhere herein.

In one aspect, as shown in FIG. 4, an extracorporeal circuit utilizes anoxygenator (e.g., Minimax Plus® hollow fiber oxygenator), a pump (e.g.,Bio-Medicus model 540 Bio-Console®with a BP50 Pediatric Bio Pump®centrifugal pump), and a warmer (Bio-Medicus model 370 BioCal™Temperature Controller). The circuit also utilizes a roller pump (e.g.,Sarns model 7000; Sarns, Ann Arbor, Mich.) to supplement for lack ofgravity return to the patient. Bridges and clamps are utilized toisolate both the perfused liver and the patient.

In an operating area within the DPF Isolation Area, a source animal isplaced under a general anesthetic (ketamine, xylazine, enflurane) oreuthanized by captive bolt. A hepatectomy is then performed on thesource animal in designated pathogen free conditions.

The livers can be preserved in any number of ways known in the art priorto use as an extracorporeal filter, including, but not limited to, asdisclosed in Levy (e.g., “a 4° C. lactated Ringer's/albumin solution andcannulated in the portal vein (28F Research Medical, model SPC-641-28)and the inferior vena cava (36F Research Medical, model SPC-641-36)”).

The common bile duct can be intubated in any number of ways, including,but not limited to, as set forth in Levy (e.g., “with an intravenousextension tube (Extension Set 30, Abbott Hospitals, Inc., Chicago, Ill.)to allow subsequent quantification of bile production.”)

The liver product derived from the source animal can be packaged andtransported to the location of the procedure in accordance with currentpractice with human donor livers.

The procedure to utilize the liver filtration product can be performed,for example, by percutaneously cannulating a patient's internal jugularvein for venous return with a 12F pediatric arterial cannula (e.g.,Medtronic DLP, Grand Rapids, Mich.) and percutaneously cannulating apatient's femoral vein for venous outflow with a 19F femoral arterycannula (e.g., Medtronic Bio-Medicus, Eden Prairie, Minn.). Thesecannulas are connected to a bypass circuit, having a centrifugal pump(e.g., Bio-Medicus), a heat exchanger (Medtronic Bio-Medicus), anoxygenator (e.g., Medtronic Cardiopulmonary, Anaheim, Calif.), and aroller pump (e.g., Sams) incorporated therein.

This circuit is primed with crystalloids and run for a period of time(e.g., 20 minutes) before the DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pig liver is incorporatedat a stabilized flow rate of 800 ml/min, maintained in a crystalloidbath occasionally supplemented with warm solution.

The aspects of the invention described above are intended to be merelyexemplary; numerous variations and modifications will be apparent tothose skilled in the art. All such variations and modifications areintended to be within the scope of the present invention as defined inany appended claims.

Example 5

In this example, preterm swine fetuses and neonatal piglets are derivedas offspring from DPF Closed Colony, α-1,3-galactosyltransferase [Gal-T]knockout pigs, as shown and described herein in accordance with thepresent invention.

Such preterm swine fetuses and neonatal piglets are utilized as a sourcefor cells, tissues and organs for xenotransplantation therapies,including, but not limited to, in regenerative or direct transplantationtherapies. It will be understood that such cells, tissues and organs canbe utilized as fresh or following cryopreservation in accordance withthe present invention (e.g., cryopreservation in the range of −80° C.).

In one aspect, mesenchymal cells, pluripotent cells, stem cells and/orother cells that have not differentiated are harvested from such pretermswine fetuses and utilized for regenerative therapies and othertherapies as described herein, whereas such undifferentiated cells canbe found in high proportion in swine fetuses as well as in neonatalpiglets. Since these cells are derived from fetuses earlier along thegestation period, they are less differentiated and more pliable whichoffers greater potential for regenerative therapies. Furthermore, sincethese cells may be derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs, as shown anddescribed herein, they do not possess aggravating immunogenic,pathogenic and/or other aggravating factors causing rejection by thehuman immune system, and the cells will persist and differentiate insidea human recipient offering regain of function of growth of model tissueusing these genetic and cellular building blocks.

By way of example, such cells may be utilized to generate an array oforgans and/or tissues, through regenerative cell-therapy methods knownin the art (e.g., through utilization of biological scaffolds), forxenotransplantation including, but not limited to, skin, kidneys, liver,brain, adrenal glands, anus, bladder, blood, blood vessels, bones,brain, brain, cartilage, ears, esophagus, eye, glands, gums, hair,heart, hypothalamus, intestines, large intestine, ligaments, lips,lungs, lymph, lymph nodes and lymph vessels, mammary glands, mouth,nails, nose, ovaries, oviducts, pancreas, penis, pharynx, pituitary,pylorus, rectum, salivary glands, seminal vesicles, skeletal muscles,skin, small intestine, smooth muscles, spinal cord, spleen, stomach,suprarenal capsule, teeth, tendons, testes, thymus gland, thyroid gland,tongue, tonsils, trachea, ureters, urethra, uterus, uterus, and vagina,areolar, blood, adenoid, bone, brown adipose, cancellous, cartaginous,cartilage, cavernous, chondroid, chromaffin, connective tissue, dartoic,elastic, epithelial, epithelium, fatty, fibrohyaline, fibrous, Gamgee,Gelatinous, Granulation, gut-associated lymphoid, Haller's vascular,hard hemopoietic, indifferent, interstitial, investing, islet,lymphatic, lymphoid, mesenchymal, mesonephric, mucous connective,multilocular adipose, muscle, myeloid, nasion soft, nephrogenic, nerve,nodal, osseous, osteogenic, osteoid, periapical, reticular, retiform,rubber, skeletal muscle, smooth muscle, and subcutaneous tissue.

Accordingly, preterm swine fetuses and neonatal piglets may be utilizedas a source of tissue, cells and organs in accordance with the presentinvention based on their characteristics as compared to adult swine.

Example 6

Porcine skin shares fundamental properties with human skin andrepresents a potential alternative to human cadaver skin grafts fortemporary coverage of severe burns. The impact of extendedcryopreservation on porcine grafts on graft viability, graft take, andbarrier function was examined in a study using a model of MHC matchedand mismatched MHC class II skin transplants.

Cellular viability was assessed using formazan-MTT and the biologicalproperties of the grafts, were assessed by grafting on swine recipients.To complement the in vivo clinical assessments, histologic, andmorphologic analyses, a series of MTT-reduction assays were performed toevaluate the residual viability of porcine grafts after cryopreservationand long-term storage. Mitochondria reduce MTT into a formazanmetabolite, which can be observed as purple hue. Harnessing thisphenomenon, an analysis of changes in optical density values measured bya spectrophotometer, or an interpolation of the quantities of formazanproduced against standard curves, can provide differential assessmentsof cellular viability, between experimental samples and positive andnegative controls. There were 2 cohorts of 2 animals each (total, N=4)based upon the MHC match and each swine received 4 grafts: one autograftand three allografts of identical MHC-profiles. Grafts were clinicallyassessed for graft-take, adherence, and time to graft rejection.Rejection was also assessed histologically via the Banff grading scale.

Direct comparisons between otherwise equivalent materials yieldmeaningful, differential times of survival, based solely on duration ofstorage, holding all other factors constant. Side-by-side, in vivoevaluations are performed between equivalent grafts, preserved inidentical fashion, stored for periods of 15 minutes versus 7 years.Clinical gross assessments and photographs, paired with independenthistological assessments, determine whether any appreciable differencesin graft survival exist relative to the length of time in the frozenstate. In tandem, separate in vitro assessments of graft viability,quantified by MTT-reduction assays, characterize the metabolic activityof cells post-cryopreservation and various storage terms. Further,independent histomorphological analysis, using standard histological(H&E) staining, provides evidence as to whether these processes causeobservable changes to the graft material at a structural level. Thisstudy advantageously used materials that had been stored, uninterrupted,for such a time, along with the associated surgical records andstandardized institutional protocols. Further, processing methods andprotocols between the comparative groups were standardized, andidentically applied, with respect to cryopreservation and thawingprotocols, reagents, and methods employed. Combined, this allowed forisolated, side-by-side evaluation of duration of storage, and alleviatedthe need to model or extrapolate findings, or otherwise use normativepredictive methods. Furthermore, the use of MHC-matched and Class IImismatched donor-recipient pairs in this model of allogeneic skintransplantation served as internal controls to both confirm the identityof the tissues obtained seven years earlier, and the veracity of thesurgical notes and documentation. Further, equivalent behavior exhibitedby the allografts also demonstrates that the antigenicity of the graftswas not altered as a result of the duration of storage.

There were no technical failures; all grafts adhered to their respectivewound beds and re-vascularized. In cohort 1 (MHC-matched donor-recipientpair), all grafts remained adherent, and appeared uniformly healthy atpostoperative day (POD) 12 (FIG. 5A), but at POD-14, signs of necrosis,progressive erythema and loss of adherence were observed (FIG. 5B).Clinical assessment of the 6 grafts in cohort 1 showed rejection atPOD-14 to 18. In cohort 2, MHC class II mismatched, allogeneic graftsappeared comparable to autografts through POD-4. However, by POD-8, allallogeneic grafts demonstrated mild erythema, consistent with rejectionand were considered fully rejected by POD-10. No statisticallysignificant difference in the duration, quality of adherence, orcellular viability among the fresh, recently preserved, and long termpreserved skin grafts were observed. The cryopreserved materials were,statistically speaking, more alive than dead, and this finding wasempirically witnessed in vivo, as all 7-year grafts demonstratedadherence to the wound bed and prolonged survivability. Suchsurvivability would not have been exhibited by non-vital allografts.Without limiting the invention, it will be understood that the timeperiod for cryopreservation for the present invention may, for example,include any length of time up to about 7 years.

Materials and Methods:

The study was conducted in accordance an IACUC approved protocol(2005N000279, Amendment 69) at the Center for Transplantation Sciences,and in compliance with the U.S. Department of Agriculture's (USDA)Animal Welfare Act (9 CFR Parts 1, 2 and 3), the Guide for the Care andUse of Laboratory Animals, and all state, local laws and regulations.Study protocols, surgical procedures, and animal care guidelines wereindependently reviewed and monitored by a standing IACUC committee.

A total of eight swine were enrolled in this experiment, and all weremembers of the Sachs-NIH, inbred miniature swine colony. At the time ofsurgery, all swine were between 10 and 20-kg in total body weight andbetween 2 and 4 months of age. Immunosuppression regimen(s) were notadministered at any time during this experiment. Animals 24074 and 24075were assigned to Cohort 1 and represented a MHC-matched donor-recipientpair. Animals 24043 and 24070 were assigned to Cohort 2 and representeda mis-match of MHC Class II donor-recipient pair. Separately, for the invitro, MTT series of analyses, five, additional wild-type Gottingenminiature swine provided tissues for positive and negative controls.

Swine donors were anesthetized with I.M. 2 mg/kg telazol (tiletamine HCland zolazepam HCl, Zoetis Inc., Kalamazoo, Mich.) and brought to theoperating room for orotracheal intubation. Anesthesia was maintainedusing 2% isoflurane and oxygen. Skin surfaces were disinfected beforesurgery with chlorhexidine acetate (Nolvasan® Surgical Scrub, Fort DodgeAnimal Health, Fort Dodge, Iowa) and povidone-iodine, 10% (BetadineSolution, Purdue Products, L.P., Stamford, Conn.). The animals were thendraped, leaving the right side of the dorsum exposed. Split-thicknessskin grafts, measuring approximately 25 cm² (surface area) wereharvested between the scapula and inferior margin of the lowermost ribfrom each animal using an air-driven Zimmer dermatome (Medfix Solution,Inc., Tucson, Ariz.) with the depth set to 0.056-cm (0.022 inches).

Following skin graft harvest, grafts intended for cryopreservation andstorage for limited duration grafts underwent a standardizedinstitutional protocol and were maintained at −80° C. for 15 minutesprior to thawing. Long-term cryopreserved grafts had been continuouslystored at −80° C. for a period of more than 7 years. All grafts,previously sized to approximately 25 cm², were placed on a sterile nylonmesh backing for structural support and rolled for placement into athreaded seal cryovial under a laminar flow hood. Once all grafts wereprepared, approximately 5-mL of freeze media was added to the vial andsealed. The protocol required freeze media prepared by combining 15%dimethyl sulfoxide (DMSO) cryoprotective media (Lonza BioWhittaker) withfetal porcine serum (FPS) or donor serum (if FPS is unavailable) in a1:1 ratio, filtering (0.45 micron), and chilling to 4° C. prior to use.The vials were subsequently frozen in a controlled rate, phase freezerat a rate of 1° C. per minute to −40° C., then rapidly cooled to atemperature −80° C., at which they remained for 15 minutes for thosetest articles in the control group subjected to limited storageduration, or for a period of more than 7 years in the case of the thoseexperimental grafts in the test group exposed to extended duration ofcryopreservation. DMSO displaces intracellular fluid during the freezingprocess. Cryoprotective media, e.g., CryoStor is used in an amount ofabout 40-80%, or 50-70% based on maximum internal volume of the cryovial(10 ml) less the volume of the xenotransplantation product.

In order to thaw the grafts for surgical use, sealed vials were placedin 37° C. water baths for approximately 1 minute, at which point thevial was opened and the frozen graft was removed using steriletechnique. Subsequently, grafts underwent 3, 1-minute serial washes innormal saline with gentle agitation, in order to dilute andsystematically remove ambient, residual DMSO and prevent loss of cellviability. Grafts were then taken to the surgical field in normal salineat 25° C. for engraftment.

Two separate, but identical, surgical events were performed insuccession. The entire surgical plan included a total of four (n=4)donor-recipient swine, employing two animals per each of the twoexperimental cohorts (Cohort 1 and Cohort 2), paired intentionally basedon SLA-configurations as described previously. In total, four technicalcontrols and twelve (n=12) experimental grafts were engrafted andsubsequently observed.

Each animal received four deep-partial defects along the animal's rightdorsum, in a linear (caudal to cranial) orientation, ordered from 1 to4, respectively. Deep-partial wound defects were surgically introducedvia additional passes with the dermatome after the initial splitthickness graft harvest. The resulting wound beds were uniform, free ofvisible debris, and demonstrated independent, punctate bleeding. Thesedefects were interrupted, and not made in a single continuous pass withthe dermatome. Instead, care was given to create four, isolated butequivalent wounds with regards to overall size, depth, and anatomicallocation.

Following thawing, but prior to engraftment, all split-thickness skingrafts were fenestrated using a 15 (size) blade to prevent seroma orhematoma formation. Graft test articles were independently placed on theprepared wound bed and uniformly sutured in place using simpleinterrupted, 3-0 nylon sutures, applied in a graft-to-wound bed manner.Approximately 16 points of fixation were introduced per graft, spacedevenly around the graft, with the resulting knot located on the woundborder, not the graft article. This technique ensured that minimal, butadequate, residual tension was present and uniform, which is necessaryfor optimal graft-to-wound adherence, minimization of hematomas, andoptimal graft survivability.

At Wound Site 1 (most caudal), a split-thickness autograft was placed,serving as a technical control. This autograft test article washarvested during the wound bed creation, subsequently underwent the samefreeze-thaw process concomitantly with all experimental grafts, and washeld in an identical, cryopreserved state for the same duration as thecontrol grafts identified for a limited duration (15 minutes at −80°C.). At Wound Site 2, a split-thickness allograft from its respectivecohort pair-mate was sutured into place. This graft represented testarticles exposed to cryopreservation for a limited duration (15 minutesat −80° C.). At Wound Site 3, a split-thickness allograft from thewild-type donor, which represented a split-thickness graft, withidentical SLA matching as those at Wound Site 2 that had experienced“extended” storage in the cryopreserved state (more than 7 years at −80°C.). At Wound Site 4 (most cranial), a split-thickness allograft from agenetically engineered knockout donor, which represented asplit-thickness graft, with identical SLA matching as those grafts atWound Site 2, sourced from the genetically engineered donor animal, thathad also experienced “extended” exposure in the cryopreserved state(−80° C.) for more than 7 years.

Overlying pressure dressings, consisting of Xeroform petrolatum gauze(Medtronic), Telfa™ non-adhesive dressing (Covidien, Minneapolis,Minn.), and sterile gauze were maintained in place and dry withmultiple, overlapping sheets of Tegaderm™ (3M, St. Paul, Minn.).Recipients were then dressed with cotton jackets to reduce interferencewith the grafts. Graft dressings were removed on POD-2 and changed dailythereafter. Total postoperative follow up was 20 days. Animals weremonitored for signs of pain including vocalization, tachypnea, loss ofappetite, and changes in attitude, behavior, and mobility. Transdermalfentanyl patches were applied for post-operative analgesia. All sutureswere removed by POD-7.

To validate the assay method and establish boundary conditions specificto test articles of split thickness skin porcine skin, two independentassay series were performed on fresh (n=5, 5) and heat denatured samples(n=5, 5). The (geometric) average formazan produced on fresh samples was0.221±0.022-mg/mL and 0.300±0.035-mg/mL, respectively. In contrast, the(geometric) average formazan produced by heat-denatured samples was0.094±0.020-mg/mL and 0.105±0.009-mg/mL, respectively. These differenceswere statistically significant in both cases (p<0.05).

All four porcine recipients tolerated the surgical procedure andrecovered fully without incident. All sixteen (n=16) graftsre-vascularized without evidence of technical complication, anduniformly exhibited adherence to the underlying wound bed (i.e. “goodtake”). Over the course of the post-operative observational period, nografts were lost due to mechanical disturbance or exhibited any clinicalsigns of wound infection. All four (n=4) autografts at Wound Site 1healed permanently and were indistinguishable from surrounding tissuesat the study end-point, acting as a technical control for the skingrafting, cryopreservation and thawing technique.

In Cohort 1, all six (n=6) allogeneic grafts demonstrated equivalentadherence to the underlying wound bed and uniformly exhibited clinicalsigns consistent with vascularization and perfusion on postoperativedays (POD) 2 and 4. Notable, however, was the contrast (loss) of colorexhibited by the allografts that had been cryopreserved for an extendedduration. All four of these grafts appeared paler as compared to theautograft and allografts at Wound Site 2. This appearance fully resolvedin all grafts, in both Animals, by POD-6. All six (n=6) allograftsexhibited mild sloughing of the superficial epidermis by POD-8, butgrafts remained viable, adherent, and appeared otherwise healthy atinspection on POD-12. In Animal 24074, grafts at Wound Sites 2 and 3showed initial signs of necrosis, progressive erythema, and loss ofadherence by POD-14, and presented increasing signs of immune-mediatedrejection, until final rejection at POD-18. However, the allograft atWound Site 4 (most-cranial) did not similarly persist; instead, onPOD-14 this graft was significantly darker and exhibited signs ofcomplete necrosis and was clinically assessed to be fully rejected atthis time. The rapid loss of the graft 4, from viability at POD-12 tocomplete avulsion by POD-14, dissimilar and distinct from Wound Site 2and Wound Site 3, was notable. For grafts on Animal 24075, all graftswere rejected on POD-14.

In Cohort 2, animals presented similarly to those in Cohort 1 throughPOD-4, and equivalently to each other. Overall, clinical signs werecomparable in progression to the minor-mismatched grafts in Cohort 1,but at an accelerated pace. The grafts that had experienced extendedcryopreservation appeared paler at POD-2 and POD-4 than the grafts thathad not experienced cryopreservation, and all grafts showed increasedevidence of perfusion and vascularization by POD-6. By POD-8, all threeallogeneic grafts in Animal 24043, showed clear signs of rejection andwere considered fully rejected. In Animal 24070, all three allogeneicgrafts showed clear signs of rejection and were considered fullyrejected by POD-10. However, all allogeneic grafts survived at the samerate, irrespective of the genetics or length of storage.

With respect to grafts subjected to limited or extended durations ofcryopreservation, 100% of allograft comparators at Wound Sites 2 and 3(n=4 of 4) were identical with respect to clinical assessment ofduration of graft survival. Comparison of Wound Sites 2 and 4 werecoincident (n=3), with the exception of the allograft at Wound Site 4,Animal 24074, which survived until POD-14 (n=1), determined to beclinically and rejected four days prior to its counterparts.

Overall, histological assessments closely mirrored the clinicalassessments. Following surgery, all grafts, including autografts,exhibited early signs of acute inflammation during initial observationson POD-2 and 4, that later resolved with time. All allografts in Cohort2, as compared to those in Cohort 1, uniformly exhibited acceleratedprogression towards immune-mediated rejection.

Ultimately, all six (n=6) allogeneic grafts in Cohort 1, and threeallogeneic grafts (n=3) from Animal 24043 in Cohort 2, independentlydemonstrated histological and microscopic signs of rejection coterminouswith the independent gross clinical assessments. The single exceptionwere the three allografts engrafted on Animal 24070, where each graftreceived Banff scores of 4 (of 4) on POD-10, but were not deemedofficially rejected until POD-12, one assessment period (2 days) laterthan the corresponding clinical designation assigned at POD-10.

With respect to grafts subjected to limited or extended durations ofcryopreservation, 100% of allograft comparators at Wound Sites 2 and 3(n=4 of 4) were identical with respect to histological assessment ofduration of graft survival. Comparison of Wound Sites 2 and 4 werecoincident (n=3), with the exception of the allograft at Wound Site 4,Animal 24074, which survived 14 days post-operatively (n=1), determinedto be histologically rejected four days prior to its counterparts.

Neither the MTT nor the neutral red staining technique, as applied oneither testing occasion, were deemed effective for histological andmicroscopic evaluation, however the standard hemotoxylin and eosinstaining demonstrated observable tissue destruction of the heatdenatured specimens.

Overall, using a linear, mixed effect model with random intercept, themean survival of grafts at Wound Site 3 was 0.00 (95% CI: −1.10, 1.10days) less than allografts at Wound Site 2. The mean survival of graftsat Wound Site 4 was 2.00 (95% CI: 1.10, 3.10 days) less than allograftsat Wound Site 2. Histological assessment finds on average 0.5 days moresurvival than grafts assessed grossly, but this is not statisticallydistinguishable (p=0.28). Seven of the eight experimental grafts faredequivalently to their comparators. The in vivo experiments showed nostatistical difference between grafts subjected to short versuslong-term storage. With the exception of the graft at Wound Site 4 onAnimal 24074, which was assessed as fully rejected four days earlierthan its comparators, graft performance and survivability wereindistinguishable between the two groups.

As noted in previous publications, cryopreserved grafts appeared notablypaler during the early imbibition and vascularization periods. Thiscontrast was starkly evident for grafts at Wound Sites 3 and 4 in allanimals. Ultimately, grafts fully resolved and adhered to the underlyingwound bed to an equivalent degree.

Demonstrated viability was evidenced uniformly across the three,independent evaluation methods. The statistical analysis of theMTT-assay shows there was no significant difference betweencryopreserved and fresh specimens (FIG. 6A), but significant differenceswere observed between fresh and cryopreserved specimens versusheat-denatured ones (FIG. 6B). This suggests broadly that thecryopreserved materials were, statistically speaking, more alive thandead. This outcome is substantiated in the in vivo outcomes in which all7-year grafts demonstrated adherence to the wound bed and prolongedsurvivability, which would not be exhibited by non-vital grafts.

Regarding the MTT-reduction assays, substantial variability existedbetween absolute values resulting from such assays, from specimen tospecimen and from cohort-to-cohort. Indeed, absolute values of formazanproduction were actually higher than those obtained fromnon-cryopreserved samples; it is unlikely that freezing enhancedcellular activity.

Pig skin can be cryopreserved for years, e.g., 1, 3, 5, 7 or more yearsand retain cell viability and that the genetic modification, Gal-T-KO,did not impact metabolic stability when compared to wild type pig skinprocessed and stored using the same procedures.

Furthermore, the use of MHC-matched and class II mismatcheddonor-recipient pairs in this model of allogeneic skin transplantationserved as internal controls to compare the effect of long termcryopreservation (7 years) on the survival of allogeneic skin grafts.The cell viability data after long term cryopreservation is supported bythe survival of the skin in vivo. This also demonstrated that thegenetic differences (wild type versus Gal-T-KO) of the grafts did notimpact the survival of the grafts.

The hypothesis was that graft take, and overall survival, would beinversely proportional to the length of storage duration. In otherwords, it was expected that the longer the graft had been frozen, theless likely it would survive and mimic the comparator grafts preservedfor shorter durations. Surprisingly, these studies revealed that theporcine tissue can be cryopreserved for significant durations, 7 yearsin the case of the present disclosure, and retain adequate cellviability. Moreover, the genetic modification (Gal-T-KO) did not impactmetabolic activity, when compared to wild type skin processedidentically. Lastly, the results confirm that the MTT-reduction assaycan reliably provide an accurate, useful diagnostic method, andapplicable to the assessment of porcine skin graft viability.

The promising results of this study indicate that it may be feasible tocryopreserve and store porcine skin for logistically relevant durations,and our findings are consistent with current industry practices and themulti-year “shelf life” guidance that the American Association forTissue Banks has established for human cadaveric tissues.

Further, these data indicate that scalable, clinically useful methods ofpreserving and storing porcine xenotransplantation products withadequate viability are disclosed, and that vital porcinexenotransplantation products that can be effectively stored anddistributed.

Example 7

It will be understood that, in the context of swine-to-humanxenotransplantation, each human recipient will have a majorhistocompatibility complex (MHC) (Class I, Class II and/or Class III)that is unique to that individual and will not match the MHC of thedonor swine. Accordingly, it will be understood that when a donor swinegraft is introduced to the recipient, the swine MHC molecules themselvesact as antigens, provoking an immune response from the recipient,leading to transplant rejection.

Human leukocyte antigen (HLA) genes show incredible sequence diversityin the human population. For example, there are >4,000 known alleles forthe HLA-B gene alone. The genetic diversity in HLA genes in whichdifferent alleles have different efficiencies for presenting differentantigens is believed to be a result of evolution conferring betterpopulation-level resistance against the wide range of differentpathogens to which humans are exposed. This genetic diversity alsopresents problems during xenotransplantation where the recipient'simmune response is the most important factor dictating the outcome ofengraftment and survival after transplantation.

In accordance with one aspect the present invention, a donor swine isprovided with a genome that is biologically engineered to express aspecific set of known human HLA molecules. Such HLA sequences areavailable, e.g., in the IPD-IMGT/HLA database (available atebi.ac.uk/ipd/imgt/hla/) and the international ImMunoGeneTicsInformation System® (available at imgt.org). For example, HLA-A1, B8,DR17 is the most common HLA haplotype among Caucasians, with a frequencyof 5%. Thus, the disclosed method can be performed using the knownMHC/HLA sequence information in combination with the disclosuresprovided herein.

In some aspects, the recipient's human leukocyte antigen (HLA) genes andMHC (Class I, II and/or III), are identified and mapped. It will beunderstood that ascertaining the human recipient's HLA/MHC sequence canbe done in any number of ways known in the art. For example, HLA/MHCgenes are usually typed with targeted sequencing methods: eitherlong-read sequencing or long-insert short-read sequencing.Conventionally, HLA types have been determined at 2-digit resolution(e.g., A*01), which approximates the serological antigen groupings. Morerecently, sequence specific oligonucleotide probes (SSOP) method hasbeen used for HLA typing at 4-digit resolution (e.g., A*01:01), whichcan distinguish amino acid differences. Currently, targeted DNAsequencing for HLA typing is the most popular approach for HLA typingover other conventional methods. Since the sequence-based approachdirectly determines both coding and non-coding regions, it can achieveHLA typing at 6-digit (e.g., A*01:01:01) and 8-digit (e.g.,A*01:01:01:01) resolution, respectively. HLA typing at the highestresolution is desirable to distinguish existing HLA alleles from newalleles or null alleles from clinical perspective. Such sequencingtechniques are described in, for example, Elsner H A, Blasczyk R: (2004)Immunogenetics of HLA null alleles: implications for blood stem celltransplantation. Tissue antigens. 64 (6): 687-695; Erlich R L, et al(2011) Next-generation sequencing for HLA typing of class I loci. BMCgenomics. 12: 42-10.1186/1471-2164-12-42; Szolek A, et al. (2014)OptiType: Precision HLA typing from next-generation sequencing data.Bioinformatics 30:3310-3316; Nariai N, et al. (2015) HLA-VBSeq: AccurateHLA typing at full resolution from whole-genome sequencing data. BMCGenomics 16:S7; Dilthey A T, et al. (2016) High-accuracy HLA typeinference from whole-genome sequencing data using population referencegraphs. PLoS Comput Biol 12:e1005151; Xie C., et al. (2017) Fast andaccurate HLA typing from short-read next-generation sequence data withxHLA 114 (30) 8059-8064, each of which is incorporated herein in itsentirety by reference.

The known human HLA/MHC or an individual recipient's sequenced HLA/MHCsequence(s) may be utilized as a template to modify the swine leukocyteantigen (SLA)/MHC sequence to match, e.g., to have 90%, 95%, 98%, 99%,or 100% sequence homology to a known human HLA/MHC sequence or the humanrecipient's HLA/MHC sequence. Upon identifying a known human recipientHLA/MHC sequence to be used or performing genetic sequencing of a humanrecipient to obtain HLA/MHC sequences, biological reprogramming may beperformed to SLA/MHC sequences in cells of the swine based on desiredHLA/MHC sequences. For example, several targeting guide RNA (gRNA)sequences are administered to the swine of the present disclosure toreprogram SLA/MHC sequences in cells of the swine with the templateHLA/MHC sequences of the human recipient.

CRISPR-Cas9 is used to mediate rapid and scarless exchange of entire MHCalleles at specific native locus in swine cells. Multiplex targeting ofCas9 with two gRNAs is used to introduce single or double-strandedbreaks flanking the MHC allele, enabling replacement with the templateHLA/MHC sequence (provided as a single or double-stranded DNA template).In certain aspects, the CRISPR/Cas9 components are injected into swineoocytes, ova, zygotes, or blastocytes prior to transfer into fostermothers.

In certain aspects, the present disclosure includes embryogenesis andlive birth of SLA-free and HLA-expressing biologically reprogrammedswine. In certain aspects, the present disclosure includes breedingSLA-free and HLA-expressing biologically reprogrammed swine to createSLA-free and HLA-expressing progeny. In certain aspects, the CRISPR/Cas9components are injected into swine zygotes by intracytoplasmicmicroinjection of porcine zygotes. In certain aspects, the CRISPR/Cas9components are injected into swine prior to selective breeding of theCRISPR/Cas9 genetically modified swine. In certain aspects, theCRISPR/Cas9 components are injected into donor swine prior to harvestingcells, tissues, zygotes, and/or organs from the swine. In certainaspects, the CRISPR/Cas9 components include all necessary components forcontrolled gene editing including self-inactivation utilizing governinggRNA molecules as described in U.S. Pat. No. 9,834,791 (Zhang), which isincorporated herein by reference in its entirety.

The genetic modification can be made utilizing known genome editingtechniques, such as zinc-finger nucleases (ZFNs), transcriptionactivator-like effector nucleases (TALENs), adeno-associated virus(AAV)-mediated gene editing, and clustered regular interspacedpalindromic repeat Cas9 (CRISPR-Cas9). These programmable nucleasesenable the targeted generation of DNA double-stranded breaks (DSB),which promote the upregulation of cellular repair mechanisms, resultingin either the error-prone process of non-homologous end joining (NHEJ)or homology-directed repair (HDR), the latter of which can be used tointegrate exogenous donor DNA templates. CRISPR-Cas9 may also be used toremove viral infections in cells. For example, the genetic modificationvia CRISPR-Cas9 can be performed in a manner described in Kelton, W. et.al., “Reprogramming MHC specificity by CRISPR-Cas9-assisted cassetteexchange,” Nature, Scientific Reports, 7:45775 (2017) (“Kelton”), theentire disclosure of which is incorporated herein by reference.Accordingly, the present disclosure includes reprogramming usingCRISPR-Cas9 to mediate rapid and scarless exchange of entire alleles,e.g., MHC, HLA, SLA, etc.

In one aspect, the recipient's HLA/MHC gene is sequenced and templateHLA/MHC sequences are prepared based on the recipient's HLA/MHC genes.In another aspect, a known human HLA/MHC genotype from a WHO databasemay be used for genetic reprogramming of swine of the presentdisclosure. CRISPR-Cas9 plasmids are prepared, e.g., using polymerasechain reaction and the recipient's HLA/MHC sequences are cloned into theplasmids as templates. CRISPR cleavage sites at the SLA/MHC locus in theswine cells are identified and gRNA sequences targeting the cleavagesites and are cloned into one or more CRISPR-Cas9 plasmids. CRISPR-Cas9plasmids are then administered into the swine cells and CRIPSR/Cas9cleavage is performed at the MHC locus of the swine cells.

The SLA/MHC locus in the swine cells are replaced with one or moretemplate HLA/MHC sequences matching the known human HLA/MHC sequences orthe recipient's sequenced HLA/MHC genes. Cells of the swine aresequenced after performing the SLA/MHC reprogramming steps in order todetermine if the HLA/MHC sequences in the swine cells have beensuccessfully reprogrammed. One or more cells, tissues, and/or organsfrom the HLA/MHC sequence-reprogrammed swine are transplanted into ahuman recipient.

In certain aspects, HLA/MHC sequence-reprogrammed swine are bred for atleast one generation, or at least two generations, before their use as asource for live tissues, organs and/or cells used inxenotransplantation. In certain aspects, the CRISPR/Cas9 components canalso be utilized to inactivate genes responsible for PERV activity,e.g., the pol gene, thereby simultaneously completely eliminating PERVfrom the swine donors.

For purposes of modifying donor SLA/MHC to match recipient HLA/MHC,comparative genomic organization of the human and swinehistocompatibility complex has been mapped. For example, such SLA to HLAmapping can be found in: Lunney, J., “Molecular genetics of the swinemajor histocompatibility complex, the SLA complex,” Developmental andComparative Immunology 33: 362-374 (2009) (“Lunney”), the entiredisclosure of which is incorporated herein by reference. Accordingly, aperson of ordinary skill in the art effectively and efficientlygenetically reprogram swine cells in view of the present disclosure andusing the mapping of Lunney et al. as a reference tool.

The modification to the donor SLA/MHC to match recipient HLA/MHC causesexpression of specific MHC molecules from the swine cells that areidentical, or virtually identical, to the MHC molecules of a known humangenotype or the specific human recipient. In one aspect, the presentdisclosure involves making modifications limited to only specificportions of specific SLA regions of the swine's genome to retain aneffective immune profile in the swine while biological products arehypoimmunogenic when transplanted into human recipients such that use ofimmunosuppressants can be reduced or avoided. In contrast to aspects ofthe present disclosure, xenotransplantation studies of the prior artrequired immunosuppressant use to resist rejection. In one aspect, theswine genome is reprogrammed to knock-out swine genes corresponding toHLA-A, HLA-B, HLA-C, and DR, and to knock-in HLA-C, HLA-E, HLA-G. Insome aspects, the swine genome is reprogrammed to knock-out swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and to knock-inHLA-C, HLA-E, HLA-G. In some aspects, the swine genome is reprogrammedto knock-out swine genes corresponding to HLA-A, HLA-B, HLA-C, HLA-F,DQ, and DR, and to knock-in HLA-C, HLA-E, HLA-G, HLA-F, and DQ. In oneaspect, the swine genome is reprogrammed to knock-out SLA-11; SLA-6,7,8;SLA-MIC2; and SLA-DQA; SLA-DQB1; SLA-DQB2, and to knock-in HLA-C; HLA-E;HLA-G; and HLA-DQ. In certain aspects, HLA-C expression is reduced inthe reprogrammed swine genome. By reprogramming the swine cells to beinvisible to a human's immune system, this reprogramming therebyminimizes or even eliminates an immune response that would haveotherwise occurred based on swine MHC molecules otherwise expressed fromthe donor swine cells.

It will therefore be understood that this aspect (i.e., reprogrammingthe SLA/MHC to express specifically selected human MHC alleles), whenapplied to swine cells, tissues, and organs for purposes ofxenotransplantation will decrease rejection as compared to cells,tissues, and organs derived from a wild-type swine or otherwisegenetically modified swine that lacks this reprogramming, e.g.,transgenic swine or swine with non-specific or different geneticmodifications.

It will be further understood that causing the donor swine cells,tissues, and organs to express a known human MHC genotype or therecipient's MHC specifically as described herein, combined with theelimination in the donor swine cells of alpha-1,3-galactosytransferase,Neu5Gc, and β1,4-N-acetylgalactosaminyltransferase (B4GALNT2) (e.g.,“single knockout,” “double knockout,” or “triple knockout”), presents aswine whose cells will have a decreased immunological rejection ascompared to a triple knockout swine that lacks the specific SLA/MHCreprogramming of the present disclosure.

Example 8

Various cellular marker combinations in swine cells are made and testedto prepare biologically reprogrammed swine cells for acceptance by ahuman patient's body for various uses. For these tests, Porcine AortaEndothelial Cells (PAECs) and/or a transformed porcine macrophage cellline available from ATCC® (3D4/21) are used. Cell samples to be testedinclude the following:

-   -   1. PAEC wild type;    -   2. PAEC class II SLA DQ Knock out (KO);    -   3. PAEC class II SLA DQ KO+HLA DQ Knock In (KI);    -   4. PAEC class II SL DR Knock out (KO);    -   5. PAEC class II SLA DR KO+HLA Dr Knock In (KI);    -   6. PAEC class II SLA DP Knock out (KO); and    -   7. PAEC class II SLA DP KO+HLA DP Knock In (KI).        Or for 3D4/21 cells:    -   1) Knock out surface sugar glycans (GGTA1, CMAH and B4GALNT2)    -   2) Knock out all MHC I    -   3) Trial 1        -   a. Knock out DP, DQ, and DR_(α)        -   b. Replace DR_(β) with its human equivalent    -   4) Trial 2        -   a. Knock out DQ, DR, and DP_(α)        -   b. Replace DP_(β) with its human equivalent    -   5) Trial 1        -   a. Knock out DR, DP, and DQ_(α)        -   b. Replace DQ_(β) with its human equivalent

The Knockout only and knockout plus knock in cell pools are generated bydesigning and synthesizing a guide RNA for the target gene. Each guideRNA is composed of two components, a CRISPR RNA (crRNA) and atrans-activating RNA (tracrRNA). These components may be linked to forma continuous molecule called a single guide RNA (sgRNA) or annealed toform a two-piece guide (cr:tracrRNA).

CRISPR components (gRNA and Cas9) can be delivered to cells in DNA, RNA,or ribonucleoprotein (RNP) complex formats. The DNA format involvescloning gRNA and Cas9 sequences into a plasmid, which is then introducedinto cells. If permanent expression of gRNA and/or Cas9 is desired, thenthe DNA can be inserted into the host cell's genome using a lentivirus.Guide RNAs can be produced either enzymatically (via in vitrotranscription) or synthetically. Synthetic RNAs are typically more purethan IVT-derived RNAs and can be chemically modified to resistdegradation. Cas9 can also be delivered as RNA. The ribonucleoproteins(RNP) format consists of gRNA and Cas9 protein. The RNPs arepre-complexed together and then introduced into cells. This format iseasy to use and has been shown to be highly effective in many celltypes.

After designing and generating the guide RNA, the CRISPR components areintroduced into cells via one of several possible transfection methods,such as lipofection, electroporation, nucleofection, or microinjection.After a guide RNA and Cas9 are introduced into a cell culture, theyproduce a DSB at the target site within some of the cells. The NHEJpathway then repairs the break, potentially inserting or deletingnucleotides (indels) in the process. Because NHEJ may repair the targetsite on each chromosome differently, each cell may have a different setof indels or a combination of indels and unedited sequences.

For knock in cells, the desired sequences are knocked into the cellgenome through insertion of genomic material using, e.g.,homology-directed repair (HDR). To optimize expression of class IImolecules, the cells are incubated in porcine interferon gamma (IFN-γ)for 72 hours which stimulates expression. Expression is then measured byflow cytometry using target specific antibodies. Flow cytometry mayinclude anti-HLA-C, HLA-E, HLA-G, or other HLA antibodies, or pananti-HLA class I or class II antibodies. According to the presentdisclosure, cell surface HLA expression after knock-in is confirmed.

Complement Dependent Cytotoxicity (CDC) assays may be performed todetermine if anti-HLA antibodies recognize the cells from the biologicalproduct of the present disclosure. Assay plates prepared by adding aspecific human serum containing previously characterized anti-HLAantibodies (or control serum) can be used. IFN-γ treated donor cells areresuspended and added to the assay plates, incubated with a source ofcomplement, e.g., rabbit serum. After at least 1 hour of incubation atroom temperature, acridine orange/ethidium bromide solution is added.Percent cytotoxicity is determined by counting dead and live cellsvisualized on a fluorescent microscope, subtracting spontaneous lysisvalues obtained in the absence of anti-HLA antibodies, and scoring witha scale.

For 3D4/21 cells:

When knocking out surface sugar glycans, a cell line that does notexpress the sugar moieties is obtained, so there is no binding ofnatural preformed antibodies found in human serum. This is detectedusing flow cytometry and human serum and a labeled goat anti human IgGor IgM antibody; or specific antibodies directed against sugars. Theresult is no binding of the antibodies to the final cell line. Positivecontrol is the original cell line (WT) without genetic modifications. Inaddition, a molecular analysis demonstrates changes in those genes.

In knocking out expression of SLA class I molecules using CRISPRtechnologies, the resulting cell line lacks the above sugar moieties aswell as SLA class I expression. Analysis by flow cytometry and moleculargene are performed to demonstrate no surface expression and changes madeat the gene level. Cellular reactivity is assessed using a mixedlymphocyte reaction (MLR) with human PBMCs and the irradiated cell line.In comparison to the WT line, there is a reduction in the T cellproliferation, predominantly in the CD8+ T cells.

Expression of SLA Class II molecules, DR and DQ, is performed by onlyknocking out the alpha gene of the heterodimer. Because there is noporcine DP, the resulting cell line lacks expression of any of the MHCmolecules. Analysis is performed at the molecular level, cell surfaceexpression, and in vitro reactivity with human PBMC. There is asignificant downward modulation of reactivity against the resulting cellline.

Human class II, DR-beta gene is knocked in. Similar analysis isperformed, but a human donor who would have the same DR beta would alsobe used. The swine DR alpha is expected to bind to the human DR beta dueto the high homology of the alpha molecules and express on the cellsurface, a donor with the same DR is expected to not react. In someaspects, both human alpha and beta genes of the DR are knocked in.Analogous trials are conducted with DP-beta and DQ-beta genes knockedin.

For PAECs:

To test for cellular reactivity, the PAECs are incubated with porcineIFN-γ for 72 hours then human CD4+ T cells are added to the PAECs andcultured for 7 days. The readout is a form of activation/proliferationdepending on the resources available.

Potential observations are:

-   -   1. Unstimulated WT PAEC: No response    -   2. Stimulated PAEC: Positive response    -   3. Stimulated class II SLA DQ KO: No response    -   4. Stimulated class II SLA DQ KO+HLA DQ KI: no response or        reduced response compared to #2.

To observe a specific response to DQ, human antigen presenting cells(APCs) are absent from the culture such that the cellular response isnot the result of pig antigens presented by the APCs.

Upon confirmation of study results, genetically reprogrammed pigs arebred so that several populations of pigs are bred, each populationhaving one of the desirable human cellular modifications determined fromthe above assays. The pigs' cellular activity after full growth isstudied to determine if the pig expresses the desired traits to avoidrejection of the pigs' cells and tissues after xenotransplantation.Thereafter, further genetically reprogrammed pigs are bred having morethan one of the desirable human cellular modifications to obtain pigsexpressing cells and tissues that will not be rejected by the humanpatient's body after xenotransplantation.

Any of the above protocols or similar variants thereof can be describedin various documentation associated with a medical product. Thisdocumentation can include, without limitation, protocols, statisticalanalysis plans, investigator brochures, clinical guidelines, medicationguides, risk evaluation and mediation programs, prescribing informationand other documentation that may be associated with a pharmaceuticalproduct. It is specifically contemplated that such documentation may bephysically packaged with cells, tissues, reagents, devices, and/orgenetic material as a kit, as may be beneficial or as set forth byregulatory authorities.

Example 9 Product Processing Generally

A xenotransplantation product of the present disclosure was processedaccording to the following procedures.

Personnel

The operator was dressed in sterile dress in accordance withinstitutional standards to maintain designated pathogen free conditions.The operator wore eye protection safety glasses for ultraviolet lightand lasers.

Preparation of Laminar Flow Hood and Product Processing

An ultraviolet laser lamp (Model #) was set up in a laminar flow hood.Each of the four corners of the lamp was placed on two container lidsthat were stacked on top of each other, i.e., four pairs of lids wereused to support the lamp. The distance from the lamp bulbs (2 bulb tubestotal) to the floor of the hood was approximately 1.5 inches. The entireinterior of the hood was sprayed with alcohol, e.g., ethanol orisopropanol. The lamp was turned on and the operator performed acalculation of time for desired exposure based on lamp specifications,number of bulbs, and distance between the bulbs and thexenotransplantation product.

The operator poured two baths (one chlorhexidine and one alcohol) intotwo separate bowls and placed the two bowls under the hood.

A package of new sterilized vials was placed under the hood. Vial capswere unscrewed and placed into the chlorhexidine bath. Each vial(without cap) was then turned upside down and plunged open ended intothe chlorhexidine bath, for one minute each and then set upright to airdry. Thereafter, the exterior of each vial was wiped with chlorhexidineand alcohol utilizing sterile gauze. The vial caps were removed from thechlorhexidine bath and placed on sterile gauze. The open ends of eachvial were plunged into alcohol bath for 1 minute each and then set asideto air dry.

A xenotransplantation product “#46 product” (5×15 cm) having a meshbacking prepared according to Example 2 was removed from its originalvial and the operator placed original vial into an empty bowl. Operatorplaced the #46 product on the paper side of an opened sterilizedinstrument package. The operator unrolled the #46 product and placed itunder the lamp for 2 minutes, then turned it over to the other side,removed the mesh backing, and put it under the lamp for 2 minutes onopposite side, while still on the same paper. The time period forexposing a given sample to the UV light can be varied based on thespecific biological agents or the types of biological agents to besterilized, e.g., as shown in the following Table 13:

TABLE 13 Type of UV-C Dosage Sterilization Biological (uW sec/cm²) timeBiological Agent Agent for 90% sterilization (sec)* Penicillium spp.Fungus 224,000 1800 Aspergillus flavus Fungus 34,900 300 Aspergillusniger Fungus 31,500 250 Yeast Fungus 4000 30 Influenza A Virus 1900 15HIV-1 Virus 28,000 220 Vaccinia Virus 1500 10 Escherichia coli Bacteria2000 20 Staphylococcus Bacteria 6600 50 aureus Bacillus subtilisBacteria 6800 50 Mycoplasma spp. Bacteria 8400 70 Pseudomonas Bacteria2200 20 aeruginosa *Using a UV-C intensity of 125 uW/cm²

Then the “#46 product was removed and cut in half. Each half was rolledby hand and placed into a new vial sterilized as explained above. Eachnew cap was placed on each new vial and screwed on securely. Each vialwas placed under the lamp and periodically rolled for desired evenexposure to light on the exterior of the vial. The vials were placedinside a glass jar that had an interior that had been previouslysterilized and the exterior was sterilized by the operator with alcoholand chlorhexidine, including threads and caps.

A similar process was performed for the following xenotransplantationproducts, except instead of being placed on sterile paper prior to entryunder the lamp, the mesh was not removed from the products and theproducts were placed under the lamp skin side up for 2 minutes, then theproducts were folded over so a first half of the bottom portion of eachproduct faced the lamp for 2 minutes, then the second half of eachproduct was folded over so that the other half of the bottom of eachproduct faced the lamp for 2 minutes. Some of the products were cut intosmaller sections and exposed to light, some for periods for longer than2 minutes, but never less than 2 minutes.

Products #40 (5×15 cm), #63 (10×15 cm), #69 (10×15 cm), and #25,underwent the above processes and products #69 and #25 were rolledexclusively using instruments and the operator did not directly handlethose products. As with #46, after operator securely screwed the cap oneach vial, each vial was placed under the lamp and rolled for evenexposure to light emitted from lamp. Vials were later removed from underthe lamp and wiped down with alcohol prior to being placed into glassjars.

Four glass jars were utilized to store each of the sets of vials. Priorto being handed to the operator, the assistant drenched the exteriors ofthe glass jars with alcohol via a spray bottle. The assistant handed theglass jars to the operator by holding the bottom of each jar and handingto operator outside of hood. After receiving the glass jars fromassistant, under the hood, the operator bathed the glass jar lids andplunged the open ends of the jars into alcohol and wiped the exterior ofthe jars with alcohol including threads of the jar.

The vials were wiped with alcohol utilizing gauze and placed inside eachglass jar with an instrument. The lids of the glass jars were thensecured and the jars were handed to the assistant. Frequently and on aperiodic basis throughout these processes the assistant sprayed theoperator's gloves and arms with alcohol.

Thereafter, the products were placed into the phase freezer at theconclusion of the procedures.

Example 10

A clinical trial to evaluate the safety and tolerability ofxenotransplantation skin for coverage of severe and extensive, deeppartial and full thickness burn wounds is conducted.

A primary endpoint includes assessing the safety and tolerability of axenotransplantation skin product of the present disclosure after 28 dayswhen applied as temporary coverage to severe and extensive, deep partialor full thickness burn wounds prior to autograft placement. Safetyendpoints include incidence and severity of adverse events, changes inphysical examination, changes in vital signs, changes inelectrocardiograms, changes in hematology, serum chemistry, urinalysis,incidence of porcine endogenous retroviral (PERV) RNA present inrecipient peripheral blood, as demonstrated by RT-PCR assays, andincidence and severity of local infections. PERV testing includes PCR ofthe subject's PBMC for PERV DNA sequence, RT-PCR of subject's PBMC forPERV RNA, and serologic analysis for PERV-specific antibodies.

Secondary endpoints include: 1) assessing the long-term safety andtolerability of a xenotransplantation skin product of the presentdisclosure when applied as temporary coverage to severe and extensive,deep partial or full thickness burn wounds prior to autograft placement;2) assessing the duration of temporary barrier function afforded by thexenotransplantation skin product of the present disclosure; 3)characterizing the incidence of local wound infections at sites treatedwith the xenotransplantation skin product of the present disclosure; 4)assessing the ease and method of removal of the xenotransplantation skinproduct of the present disclosure; 5) characterizing and describing theprogression and quality of the temporary barrier function provided tothe subject, via the engraftment of a xenotransplantation skin productof the present disclosure from the time of initial graft placementfollowing wound debridement to the time of loss of effective barrierfunction, resulting from: The time of graft rejection via graft-hostimmunological response (as determined by the Clinical Wound AssessmentScale); mechanical disturbance or disruption (shear forces or hematoma);or intentional removal per Investigator's direction consistent withsubject's overall clinical course.

Further objectives include exploring the incidence and characterizingthe quality of definitive wound closure following autograft placement atsites treated with the xenotransplantation skin product of the presentdisclosure as compared to similar wound sites treated with human cadaverallograft, exploring the incidence and quality of hypertrophic scarringat sites treated with the xenotransplantation skin product of thepresent disclosure as compared to similar wound sites treated with humancadaver allograft, and exploring the severity of scar formation at sitestreated with the xenotransplanted skin product of the present disclosureas compared to similar wound sites treated with human cadaver allograft.Incidence and severity of scaring is assessed using the modifiedVancouver Scar Scale (mVSS). The mVSS is shown in the following Table14:

TABLE 14 Characteristic Item Number Vascularity Normal 0 Pink 1 Red 2Purple 3 Pigmentation Normal 0 Hypopigmentation 1 Mixed 2Hyperpigmentation 3 Pliability Normal 0 Firm 1 Ropes 2 Contracture 3Height Flat 0 <2 mm 1 >2 < 5 mm 2 >5 3 Legend: 0 = best; 12 = worst

The xenotransplantation skin product of the present disclosure ispackaged in a clear plastic, externally threaded, polypropylene vialwith threaded seal-cap, stored on a rolled, sterile nylon mesh backingon the dermal-side of the product that serves to support and protect theproduct during processing and transport. Each product is individuallyimmersed in a sterile cryoprotective medium with 5% dimethyl sulfoxide(DMSO). Source animal serum is NOT included or used in this process. Thecontents are cryopreserved via controlled rate, phase freezer and storedat about −80° C. until use.

The product is be placed on the burn wound and secured in place viasuturing or stapling. The product remains in place until it is no longerproviding effective barrier function to the wound bed, resulting fromeither: the time of product rejection via graft-host immunologicalresponse (as determined by the Clinical Wound Assessment Scale),mechanical disturbance or disruption (shear forces or hematoma), orintentional removal consistent with subject's overall clinical course.Subjects are monitored via a passive and active screening program usingblood samples collected at time points throughout the study period,including for immunogenicity testing. Immunogenicity monitoring includesassaying serum total IgG and IgM levels, human anti-porcine antibodies,and assays to determine whether cell-mediated immune reactions areoccurring.

The Clinical Wound Assessment Scale is shown in FIG. 32. Hematologytests include red blood cells (RBC), white blood cells (WBC) withdifferential (% and absolute), hemoglobin, hematocrit, platelets,prothrombin time (PT)/international normalized ratio (INR). Serumchemistry tests include ALT, Albumin, Alkaline phosphatase Amylase,Lipase, AST, Total bilirubin Direct bilirubin Total protein Creatinine,Blood urea nitrogen Creatine kinase, γ-glutamyl transferase (GGT),Potassium, Sodium, Glucose, Chloride, Bicarbonate, Calcium. Urinalysistests include pH, specific gravity Protein, Glucose, Blood, Nitrite.

Based on results in non-human primates, it is expected that graftdislocation of grade 0, 1, or 2 will be observed. Based on results innon-human primates, it is expected that graft adherence of grade 3, 4,or 5 will be observed. Based on results in non-human primates, it isexpected that granulation tissue having grade 3 or 4 will be observed.Based on results in non-human primates, it is expected thathyper-granulation grade 0, 1, or 2 will be observed. Based on results innon-human primates, it is expected that hematoma of grade 0, 1, or 2will be observed. Based on results in non-human primates, it is expectedthat fibrin deposition of grade 0, 1, or 2 will be observed. Based onresults in non-human primates, it is expected that normal or pinkvascularity will be observed. Based on results in non-human primates, itis expected that normal, mixed, or hypopigmentation will be observed.Based on results in non-human primates, it is expected that normal orfirm pliability will be observed. Based on results in non-humanprimates, it is expected that flat or <2 mm scar height will beobserved.

Example 11

Xenogeneic kidney derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least fourteen months isobserved in each of the non-human primate and the human. In someaspects, it is expected that survival of at least 24 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 36 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 48 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 60 months is observed in each of the non-human primate and thehuman.

Example 12

Xenogeneic lung derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least 30 days is observed ineach of the non-human primate and the human. In some aspects, it isexpected that survival of at least 3 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 6 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 12 months is observed in each of the non-human primate and thehuman. In some aspects, it is expected that survival of at least 24months is observed in each of the non-human primate and the human. Insome aspects, it is expected that survival of at least 36 months isobserved in each of the non-human primate and the human. In someaspects, it is expected that survival of at least 48 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 60 months is observed in each of thenon-human primate and the human.

Example 13

Xenogeneic liver derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least 60 days is observed ineach of the non-human primate and the human. In some aspects, it isexpected that survival of at least 3 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 6 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 12 months is observed in each of the non-human primate and thehuman. In some aspects, it is expected that survival of at least 24months is observed in each of the non-human primate and the human. Insome aspects, it is expected that survival of at least 36 months isobserved in each of the non-human primate and the human. In someaspects, it is expected that survival of at least 48 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 60 months is observed in each of thenon-human primate and the human.

Example 14

Xenogeneic heart derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least 20 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 24 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 36 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 48 months is observed in each of the non-human primate and thehuman. In some aspects, it is expected that survival of at least 60months is observed in each of the non-human primate and the human.

Example 15

Xenogeneic nerve tissue derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least 75 days is observed ineach of the non-human primate and the human. In some aspects, it isexpected that survival of at least 3 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 6 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 12 months is observed in each of the non-human primate and thehuman. In some aspects, it is expected that survival of at least 24months is observed in each of the non-human primate and the human. Insome aspects, it is expected that survival of at least 36 months isobserved in each of the non-human primate and the human. In someaspects, it is expected that survival of at least 48 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 60 months is observed in each of thenon-human primate and the human.

Example 16

Xenogeneic pancreas derived from DPF Closed Colony,α-1,3-galactosyltransferase [Gal-T] knockout pigs produced in accordancewith the present invention is transplanted into a non-human primate anda human. It is expected that survival of at least 20 months is observedin each of the non-human primate and the human. In some aspects, it isexpected that survival of at least 24 months is observed in each of thenon-human primate and the human. In some aspects, it is expected thatsurvival of at least 36 months is observed in each of the non-humanprimate and the human. In some aspects, it is expected that survival ofat least 48 months is observed in each of the non-human primate and thehuman. In some aspects, it is expected that survival of at least 60months is observed in each of the non-human primate and the human.

While the subject matter of this disclosure has been described and shownin considerable detail with reference to certain illustrative aspects,including various combinations and sub-combinations of features, thoseskilled in the art will readily appreciate other aspects and variationsand modifications thereof as encompassed within the scope of the presentdisclosure. Moreover, the descriptions of such aspects, combinations,and sub-combinations is not intended to convey that the claimed subjectmatter requires features or combinations of features other than thoseexpressly recited in the claims. Accordingly, the scope of thisdisclosure is intended to include all modifications and variationsencompassed within the spirit and scope of the following appendedclaims.

1. A non-wild type, biologically engineered swine for producing livecells and tissue that vascularize after xenotransplantation, whereinsaid swine has a biologically engineered genome such that it does notexpress one or more extracellular surface glycan epitopes, wherein saidswine is free of at least the following zoonotic pathogens: (i) Ascarisspecies, Cryptosporidium species, Echinococcus, Strongyloids sterocolis,and Toxoplasma gondii in fecal matter; (ii) Leptospira species,Mycoplasma hyopneumoniae, porcine reproductive and respiratory syndromevirus (PRRSV), pseudorabies, transmissible gastroenteritis virus(TGE)/Porcine Respiratory Coronavirus, and Toxoplasma gondii asdetermined by antibody titers; (iii) Porcine Influenza; (iv) thefollowing bacterial pathogens as determined by bacterial culture:Bordetella bronchisceptica, Coagulase-positive staphylococci,Coagulase-negative staphylococci, Livestock-associated methicillinresistant Staphylococcus aureus (LA MRSA), Microphyton and Trichophytonspp.; (v) Porcine cytomegalovirus; and (vi) Brucella suis; wherein saidswine has been maintained according to a bioburden-reducing procedure inan isolated closed herd, wherein all other animals in the isolatedclosed herd have been confirmed to be free of said zoonotic pathogens,and wherein the swine was isolated from contact with any non-humananimals and animal housing facilities outside of the isolated closedherd.
 2. The non-wild type, biologically engineered swine of claim 1,wherein said swine has a biologically engineered genome such that itdoes not express two or more types of extracellular surface glycanepitopes.
 3. The non-wild type, biologically engineered swine of claim2, wherein said swine has a biologically engineered genome such that itlacks a functional alpha-1,3-galactosyltransferase gene (GGTA1), andthus does not express a galactose-alpha-1,3-galactose epitope; and lacksa functional cytidine monophospho-N-acetylneuraminic acid hydroxylase(CMAH) gene, and thus does not express aN-Glycolylneuraminicglycolylneuraminic acid (Neu5gc) epitope.
 4. Thenon-wild type, biologically engineered swine of claim 2, wherein saidswine has a biologically engineered genome such that it lacks afunctional alpha-1,3-galactosyltransferase gene (GGTA1), and thus doesnot express a galactose-alpha-1,3-galactose epitope; and lacks afunctional cytidine monophospho-N-acetylneuraminic acid hydroxylase(CMAH) gene, and thus does not express aN-Glycolylneuraminicglycolylneuraminic acid (Neu5gc) epitope; and lacksa functional Beta-1,4-N-Acetyl-Galactosaminyltransferase 2 (B4GALNT2)gene, and thus does not express a Sd(a) epitope.
 5. The non-wild type,biologically engineered swine of claim 1, wherein said swine is producedthrough natural intercourse by parent swine also maintained in theisolated closed herd and also free of said zoonotic pathogens, andwherein said swine is birthed through live vaginal birth.
 6. Thenon-wild type, biologically engineered swine of claim 5, whereinfollowing said live vaginal birth said swine was hand reared by one ormore humans.
 7. The non-wild type, biologically engineered swine ofclaim 1, wherein said swine has undetectable levels of rickettsia,mycoplasma, transmissible spongiform encephalopathies (TSEs), andparasites.
 8. The non-wild type, biologically engineered swine of claim1, wherein bioburden-reducing procedure further comprises air filtrationof the closed herd, chemically sterilizing cages and vehicles used tohouse or transport the swine, irradiating bedding, irradiating feed, ora combination thereof.
 9. The non-wild type, biologically engineeredswine of claim 1, wherein said swine has a biologically engineeredgenome that comprises scarless exchange of one or more endogenous swineleukocyte antigen alleles with one or more human leukocyte antigenalleles.
 10. The non-wild type, biologically engineered swine of claim1, wherein said swine has a biologically engineered genome comprisingreplacement of a length of 50-70 nucleotides in one or more endogenousswine leukocyte antigens with a corresponding human leukocyte antigennucleotide region.
 11. The non-wild type, biologically engineered swineof claim 10, wherein the corresponding human leukocyte antigennucleotide region is DQ, in combination with HLA-E, HLA-G, or both HLA-Eand HLA-G.
 12. The non-wild type, biologically engineered swine of claim10, wherein the biologically engineered genome has been geneticallyreprogrammed at one or more of a Class I human leukocyte antigen (HLA),a major histocompatibility complex (MHC) II, a Fc receptor,galactose-alpha-1,3-galactose, NOD-like receptor family CARD domaincontaining 5 (NLRC5), or an immunoglobulin G (IgG).
 13. The non-wildtype, biologically engineered swine of claim 1, wherein the biologicallyengineered genome comprises a nuclear genome with swine leukocyteantigen (SLA) deletions and HLA insertions, wherein the HLA genes arefrom the human recipient, from a consensus sequence for a givenpopulation group, or from a library sequence.
 14. The non-wild type,biologically engineered swine of claim 1, wherein the biologicallyengineered genome comprises knockout of genes encoding MHC Class II DQor DR.
 15. The non-wild type, biologically engineered swine of claim 1,wherein the biologically engineered genome comprises knockout of MHCClass II DQ or DR and replacement with a human DQ or DR gene sequence.16. The non-wild type, biologically engineered swine of claim 1, whereinthe biologically engineered genome comprises knockout of swine genesencoding MHC Class I and knockin of a gene encoding HLA-C.
 17. Thenon-wild type, biologically engineered swine of claim 1, wherein thebiologically engineered genome comprises knock-out of swine genescorresponding to HLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and knock-in ofHLA-C, HLA-E, and HLA-G.
 18. The non-wild type, biologically engineeredswine of claim 1, wherein the biologically engineered genome comprisesknockout of swine genes corresponding to HLA-A, HLA-B, HLA-C, and DR,and knock-in of HLA-C, HLA-E, and HLA-G.
 19. The non-wild type,biologically engineered swine of claim 1, wherein the biologicallyengineered genome comprises knockout of swine genes corresponding toHLA-A, HLA-B, HLA-C, HLA-F, DQ, and DR, and knock-in of HLA-C, HLA-E,HLA-G, HLA-F, and DQ.
 20. The non-wild type, biologically engineeredswine of claim 1, wherein the biologically engineered genome comprisesknockout of SLA-11; SLA-6, SLA-7, SLA-8; SLA-MIC2; and SLA-DQA;SLA-DQB1; SLA-DQB2, and knock-in of: HLA-C; HLA-E; HLA-G; and HLA-DQ.21. The non-wild type, biologically engineered swine of claim 1, whereinsaid swine is produced through somatic cell nuclear transfer (SCNT). 22.The non-wild type, biologically engineered swine of claim 1, whereinsaid swine is produced through direct microinjection of engineerednucleases into an embryo.